This is an extremely complicated question to answer in its current form, so first I'm going to answer a different question that you might have asked instead since that will take much less time, and then I will answer the question you actually asked, which may involve me writing an entire book. ;)
But before I go on, I will just throw one possibility out there: could this problem simply be that you're happy at night because you're drinking and you're unhappy in the morning because the alcohol has worn off? If that's not it -- if it's a problem that is always there but is merely exacerbated by the alcohol -- read on. If that is it, stop drinking.
I'd also like to take a moment to note that I am not coming at this from the point of view of a therapist, psychologist, or what have you. I am coming at this from the point of view of someone who once could have written your question but now pretty much feels good, and even feels somewhat okay when she's unhappy.
The easy question:
Can I really become a more emotionally stable, happier person? Or is that just self-help nonsense, and we just are the way we are?
Yes, you really can, and no, we are not just stuck the way we are, though you will always be influenced by your inborn temperament, which may simply involve feeling emotions a little more intensely than most other people do.
Now, onto the question you actually asked.
Answer: Sort of.
If these mood swings are so intense that they are really making your life difficult (whether doing what you need to do in your life -- either on a daily basis or over long periods of time -- or "just" in your emotional life), then you need to go to a mental health treatment provider for help. There is nothing wrong with this -- I mean, yes, there is something wrong with it, which is that it's not really fun -- but there's nothing wrong with it in any other sense. It's the equivalent of going to the doctor if you have a broken leg. Nobody would say, "It's wrong that I have to go to the doctor for my broken leg." Nobody would use the following treatment method for a broken leg:
Notice after a while that one's leg broke some time ago, though they are not sure when.
Notice that they still have some pain in the leg, and their leg isn't working so great because the fact that it broke at some point was never addressed, and they've actually been walking on this broken leg the whole time, somehow.
Stay up at night thinking about the broken leg. Feel troubled that the leg hurts.
Write in their journal about the broken leg and decide that maybe taking vitamins or talking to their best friend might, you know, help?
Keep doing the movements that aggravate the leg the most.
Read self-help books about the right attitude for changing one's broken leg.
I'm sure you get my point, so let's move on to what you can do in the meantime, or even while you're sorting out which mental health treatment provider takes your insurance, is right for you, etc. since that might take some time.
There isn't any way you can just decide to have a better attitude, or have some sort of epiphany (not even inspired by this awesome answer! ;), or read a book, or write down enough inspirational quotes to just start feeling better by next week. You can't decide, "I am going to feel better now," and then you feel better, because clearly if that worked you would not have this problem in the first place.
If someone tells you that everything will be fixed if you just do enough yoga or start drinking wheat grass or start volunteering or any number of things, they are wrong. Those things can all be wonderful, but they are not, in and of themselves, effective "broken leg" treatments here.
But the thing you can do is this: decide to do what is necessary to feel better in slow increments over time until your quality of life has improved enough that you will look back on this question and think, "I am so happy that I no longer have to wonder that anymore!"
Then, the other thing you need to do is figure out what is necessary to feel better in slow increments.
Those two things -- deciding you will do what's necessary, and then figuring out what's necessary -- are both hard, but in different ways. The first is hard because it's a continuous decision, not one decision. You will have to keep making the decision over and over again even when it's unpleasant or difficult. The latter is hard just because it's confusing and there's a lot of advice and information you will have to sort through.
This will sometimes feel overwhelming, and I'm placing a lot on your shoulders here. I'm not, however, blaming you for how you feel or the fact that you haven't "fixed" it. "Fixing" these things is not intuitive, or else we'd all be happy. It also doesn't reflect in any way on your intelligence. Lots of very intelligent people have the exact problem you are describing.
I'm just giving all this advice because, until you find a professional -- a good professional -- to help sort all this out, you are all you've got. But it's not as scary as it sounds, because you can also get yourself some [emotional] tools, the same way the doctor uses tools for the broken leg. (Forgive me always mentioning that damn leg.)
So here are my thoughts. I'm not the one who came up with them. They are part of something called Dialectical Behavior Therapy, which was developed to help people with fast mood swings such as the ones you describe. (It's generally thought of as a treatment specifically for borderline personality disorder, but don't worry about that right now. It can help everyone with mood swings, not simply people with that disorder. It is very effective when people actually use it instead of just thinking about using it.) I'm taking a lot of these ideas from The Dialectical Behavior Therapy Skills Workbook (
http://www.amazon.com/dialectica... ), but they're also pretty general tips in DBT.
These are the first things you can do.
Start to think about what your triggers are. It's completely possible that sometimes your mood changes dramatically and quickly for no recognizable reason, but there usually is indeed a reason, even if the reason is not something that happened immediately precipitating the swing. The reason might be something like you not having gotten enough sleep the night before. So keep a short little log every day of how much you slept the night before, what sort of things you're eating (not in any obsessive detail, but large amounts of
sugar can make these things worse, so you could just note down big things like that), whether or not you exercised, etc. Also, you are already aware that alcohol is a trigger, so either stop drinking alcohol completely, or at least greatly reduce the amount that you drink when you do drink.
If one of your triggers is unavoidable, like you always feel bad in the morning, plan to do something very pleasant, even if it's something small, every day at that time. This may distract you.
There's nothing wrong with distraction. Eventually you will learn how to regulate your moods better without having to distract yourself, but for now, it's good. Do anything that brings you out of your head and into the external world. I like to make jewelry, so I'll be thinking, "Ughhh, I messed up this closed loop," (which may be an annoying thought, but it's not a depressing one) instead of, "I feel so horrible. Everything sucks."
Write up a list of all the pleasurable activities you can think of, and get it out when you need something to distract you.
In that vein, Mindfulness can distract you. At a beginner's level, just think to yourself -- well, I'll do it for you now to show you, with what's around me right now. "There's a five dollar bill next to me. The five is purple. Look at that green highlighter. I believe it has dried out by now. The desk is cluttered. The printer doesn't have any paper in it. The paper is under the desk." It can be very tedious, but it's better than thinking about how miserable one is. It also has the possibility of leading your thoughts somewhere neutral. For instance, maybe I would have ended up thinking about how I needed to buy a new notebook so I can write down little bits of stories that I think up while I'm out.
There are coping thoughts you can do. I don't mean stuff like, "Life is great!" but rather things like, "My feelings are painful right now, but it's okay to feel sad sometimes." One bad thing about a lot of self-help books is that they make it sound like you're messing it up if you ever feel quite bad. You're not. All of us feel quite bad from time to time. It happens. It doesn't mean you can't still be going down the right path to feel better over time. It's sort of like how eating one huge piece of cheesecake now and then still won't ruin your diet if your diet is pretty good most of the rest of the time. It can be liberating to realize that you can feel very sad sometimes without thinking it means you're messing up horribly or there's something fundamentally wrong with you. You don't need to fight a temporary sad mood while you are in it. I know it feels -- well, to me the very bad moods felt like ocean waves (the emotions) were crashing over me, and mentally I was kicking and screaming against the tide. What "controlling" one's moods is really about is preventing the terrible ones and then sitting through them patiently when they do happen.
If part of this is motivated by feeling bad about yourself, you might want to try thinking something like, "I'm good and nobody's perfect." Yes, you are flawed. So are the people you know who you find to be delightful and fantastic. So am I. It's not a big deal that we are flawed.
Self-soothe. Bake something that smells awesome or buy a perfume that makes you happy whenever you sniff it, even if you don't want to wear it. Get a fish and watch it swim around. Listen to somebody talking calmly and evenly on NPR. Carry something very soft in your pocket to touch when you're out. Drink cocoa.
Hmm. If I tell you every single thing you can do, it will take forever, so I'm going to finish up this answer by giving just a few more tips that have helped me the most, some less advanced and some more advanced.
Make a recording of yourself, maybe with your phone if your phone does that, telling yourself in a calming voice to just breathe deeply for a minute. Then be quiet for a minute while still recording. Then tell yourself to imagine a safe or soothing location where soothing things may be occurring (mine always involves people I love talking quietly somewhere nearby, because being around people can be very soothing for me), first using your sense of sight and looking around you. Then be quiet for a minute to let yourself imagine this. Then sense of hearing. Then quiet for a minute. Then sense of smell. Quiet for a minute. Then sense of touch. Quiet for a minute. Then come back down by just breathing deeply and slowly for a little bit. Listen to it when you need to. If you're around others, go to the bathroom or outside and listen to it with headphones.
Spend a couple minutes (or more if you like) imagining every thought that comes into your head as something coming and going, something you don't hold onto, like individual fish swimming past you in a stream or billboards passing by. There will be a lot of thoughts at first, so you may have schools of fish swimming by sometimes.
Hold an ice cube. Very distracting.
This last one is from cognitive behavioral therapy.
Learn to recognize when you are having a cognitive distortion. If somebody doesn't call you when they said they would, don't jump to conclusions (something bad must have happened to them) or mind-read (they don't like me). Don't fortune-tell (I am going to do something stupid at the party). Don't catastrophize (If I fail this test, I will never get into medical school). Or rather, when you do these things -- because we all do -- recognize them. Write down more realistic alternatives. Somebody didn't call you, so that probably means he/she got busy and/or forgot by accident. If you fail the test, maybe you will get a lower grade in the class, but it is not going to ruin your entire future.
So I've been very long-winded, and I hope I haven't been tiresome. Please check out the workbook I mentioned above. DBT truly is the best thing I know of for mood regulation.
If you feel like sending me a message at any point, I'd be happy to listen to whatever you would like to share, and I would never tell anyone else anything you would say. I also wouldn't lecture. I'm only giving so much advice here because clearly you were asking for some.
Oh. You may also want to try and channel these mood swings into interesting art, both now while you're experiencing them and later when you simply remember their intensity but no longer feel as bad as you do now.