Differing behavior. These mood swings?

Hello doctors. I have mood swings, I guess? Most of the time, I dont even realize the shift, but it definitely exists. There are days when I feel like a God, massive ego, laughing and happy for no apparent reason. Like happiness becomes my neutral mood, instead of actual neutrality. I remember saying things like "Life has no bad days, just average days" in one of these "happy" months. But then suddenly, life is the worst, I have no interest in anything, anything I pick up and pursue, I lose interest in it after a few days, I dont feel well, I get extremely low self esteem, where the smallest comment will have me crying for hours, and then thinking about it for days. How do I deal with these mood swings? Im currently going through the sadder phase of my life. A little background- I have PCOD, a general physician gave me anxiety medicines once because of my symptoms, the main symptom was constant lightheadedness. Something upsetting happened day before yesterday, I have migraines too