stomach pain-- don't know what it is... help please!

Hello! I'm a 17 year old female. My upper abdomen has been bothering me for a bit over 2 months now. I have a constant dull pain and i get sharp pains once in a while on my left side. I lost some weight and don't really have much of an appetite. I'm also have a lot of gas and my stomach always makes noises. I dropped out of school because when i woke up in the morning i couldn't eat and i would gag everyday and feel nauseous. I no longer gag but i feel nauseaous and tired and still have stomach pains.

- The first doctor i went to see told me it was nerves. but i still feel like **** and i have absolutely nothing to be nervous about.

-Another doctor thought i had an ulcer so i did an endoscopy yesterday and everything was fine.

-I also did many blood tests and an ultrasound, they checked my liver, all was fine.

The only thing was that i have a hyperactive thyroid. here are my results:

TSH                 0.280             L                mU/L        0.340-5.600
FREE T4          14.24                              pmol/L       8.00-18.00
FREET3           5.8                H               pmol/L       2.3-5.2

Hopefully that means something to someone...

They did not put me on any medication for that because they said that it wasn't "overactive enough for meds"

I have been taking pentaloc for my stomach which has kinda been helping... well it stopped the sharp pains and I got a bit more hungry. But i still didn't feel great. Now my GI told me to stop taking it because i just have a "nervous stomach". He didn't even ask me any questions or anything, and i have nothing to be nervous about.

So please, if you have any ideas of what i might have, tell me! I was kind of hoping I had an ulcer, so that it could be fixed fast. But I'm sick and tired of feeling like **** and I want to go back to school in January.

THANK YOU!!!