Severe and chronic abdominal pains

I have been suffering with severe abdominal pains for several  months now.  It started out feeling like a cigar was being shoved in the left side of my stomach for several hours a day, and escalated to a point where one day I had a sip of a drink containing some vodka and just that one tiny sip hurt so much I thought I was going to vomit and I couldn't speak for ten minutes.

When I first went to my doctor, he briefly felt the area and said it was odd that I found it tender to the touch - said maybe it's an ulcer and gave me some strong liquid antacids and a breath test for helicobactor, which came back negative.

The antacid liquid made no difference, and I worsened to a point where I lost my appetite all together and was gagging involuntarily after eating.

I went back to the doctor and was advised once again it may be an ulcer or that it may be severe gastreoentitis and was given a month's supply of 20mg omeprizole and the message "if it doesn't fix it, come back again."

Another month goes by.  I cut out coffee, spicy foods, pop and don't touch ibuprofin, all for fear of irritating my stomach further.  About two weeks into the new pills, I no longer felt pain on a daily basis - so they did do something.

Ran out - felt ok for three days.  Then, the burning pain came back, and the gagging, all within about a week.

Go back and basically get a "well, this omeprezole worked ... you probably have some sort of acid disorder - you're too young for serious gastreointestinal issues ... here's a repeat perscription.  We'll reasses in October."

The only tests I have had done on me this entire time (a period of about four months now) is the helibactor test and a couple of doctors pressing on my stomach and telling me it's abnormal that a) I feel pain when they press it at all and b) that I feel it on my side and not in my chest.  But they then tell me that "it may be an abnormal presentation of ulcers/gastreoentitis"  And no further tests are ordered, because the pills took the pain away.

I have noticed within the past few weeks a small lump in the same area where I felt the cigar-type burning when it all started, that wasn't there before (it wasn't there the last time I had my stomach pressed).

I'm worried that there might be some underlying cause to this acid disorder, especially since I didn't really have stomach problems before this.  The pain still comes back sometimes, and it's graduated from a burning pain to a horrible knifing pain - it feels like someone is trying to gut me sometimes.

I've had thyroid problems, and I've had problems with growing benign tumors (which then grew a calcified shell and went necrotic).

I just don't know where to go from here.  I'm afraid my doctors think that I'm overreacting, because I'm "too young for serious gastroentestinal issues, so it's probably just an acid problem."

I was too young for serious thyroid issues, but they happened to me ...