What am I suffering from. To do in this?

Most of the times I feel moody and sad. Some times I don't feel like talking to anyone. I feel much hungry but don't feel like eating. I feel low confidence and feel low always. These day getting angry for even small things and shouting on my family members. When some task is given to me, first thing I think is whether I can solve this. What if I fail in doing this such kind of questions will get in my mind. If someone says that task is critical, then I feel more conscious about it and fear whether I could do this. I am not sure what to do in this regard. Somewhere I read that these are the symptoms of anxiety and depression. But I am afraid of the cost need to be spent on this. I also read that we need to continue treatment for a long time etc. How much money do I need to spent to gain confidence levels and overcome these problems. Please advise.