Horrible stomach pain. I don't know whats wrong...

....its horrible. The pain has been bothering me for about a little while now. I have been to the hospital once to find out what was wrong but they didn't know what it was. They prescribed me with something but i honestly forget the name. But I know that I stopped taking them because they didn't do a thing. After that i said to myself that I would just ride it out, that was at the beginning of the month. It went away, now its been two weeks i have been riding the pain out again. I know i have been stressing and depressed for a while and now have caused a bit of an ulcer I am led to believe. But anyways at the beginning of the two weeks I experienced pain in the middle of my chest and it hurt and felt gross. Now its has moved to really hurt bellow my ribs in the center, and around my stomach. On top of that my stomach itself hurts and i get the strangest headaches that pop out of nowhere. I barely eat because it hurts to much and then my back around my ribs starts to really hurt and i can't breathe without it hurting. I can't enjoy my food because all i feel is this horrible pain and nausea, but it's not bad enough to make me throw up. Man it makes me cry to watch others able to eat normally...but i cannot. I have a horrible time with knotted muscles and it makes the pain feel worse in my back as well.  I am so depressed about it because now i have had to drop out of school because of the weird pains and nausea.  I can't even do activities anymore without hurting its stupid because I am 15 and should not need to be feeling the way I do. In 2007 I had been pretty much forced to have a HPV needle. It paralyzed my left side completely for a week. I know it has messed me up in some ways, but i try my best not to be scared about it. I don't know if that could be making anything worse or if it is even doing anything. But i know that after i got it i haven't been the same. I just really want to know whats wrong that's all. I refuse to go to doctors because they freak the living daylights outta me. But if I have to go then I will go so that I can get this mess straightened out and looked after so I can live normally. I think I feel this way because I need to do more and get out and live life more as well. Being cooped up in a house working all the time is stressful and but  i don't know and if anyone could help me out to as what these pains might be I appreciate it A LOT! thank-you.
-A Hurting Teen-