Sounds a lot like depression to me. Why don’t you think it’s depression? You put yourself down. You have crying jags. You mistrust happiness and you hold your anger and other feelings in?
I do all that. I’m being treated for depression. Now I don’t do it so much. I had the self-esteem of a clam for a while. I still don’t understand what’s wrong with me. Sometimes it feels like there’s something important missing in me that other people have—even take for granted. Other times, when I’m happier, I don’t notice the thing that is missing, but I still don’t feel whole.
I often felt like I had to be doing this to myself. Like I couldn’t be happy without being unhappy, if that makes any sense. I would deliberately (it seemed) try to sabotage myself. I’d do things that hurt myself just because that was so much easier than trying to justify being in good shape. I’m a lot older, but this may resonate with you. I’d push away people who loved me—especially my wife. I wanted to be thrown out, because that was the only way I could justify the feelings I was feeling.
When I was your age, I had no communication with my parents. They had no clue what I was going through, and I don’t even know if they would have done anything if they had known. I don’t know if I made this happen or not, but after I graduated from college, I went home and they threw me out. I felt like no one wanted me. Not my parents. Not any employers. I had few friends.
I managed to pull it together, and did all right for many years, until I got bipolar disorder. Then the depression—well, all I can say is that the way you describe what you’re going through—it sounds far too familiar.
So you might want to talk to a school counselor like @poofandmook suggested. You might want to talk to your family doctor. Or your parents—if you have a good relationship with them. Or ask to see a therapist or psychologist.