Stomach problems for a year. "Paranoid now, fear death"?

I am 18 years old. Last year in mid November 2010, I had some cambells spaghettios, the next day I kept farting a lot. I had diarrhea later in the day. I went to the emergency room a few days later after the pain and diarrhea was too much to bear. They gave me some diet advice and some medicine. I ended up getting Imodium medicine. I drank it and I felt normal and was happy that I was healed. But a few days later, the pain came back. It stayed for a long time. Its been like this for a year. I had a ultra sound which was successful, everything was normal. I had like 6 urine test and had my blood taken like 4 to 5 times. Everything is normal. The doctors said it was gastric acid. I am not sure if thats true. My stomach does feel a bit acidy sometimes but im sure if thats acid. I have been on Prevacid and prilosec and zantac and omeprazole. Prevacid helped me when I took it, I took it in like March but after I stopped, the pain came back. The other medicines did not help. The doctors put me on Prevacid again but this time it did not work. I saw a gastro doctor and he told me it was my diet. I am a vegan, he said dont eat hamburgers and fried food. I do not eat any of that now. I still eat some tomatoes and I mainly drink water. I do not know what to do. My next appointment is in April this year. What should I do, I can not wait that long. The speghattios was recalled RAW meat, I just found that out. I became a vegan two months after the incident, only if I was a vegan earlier.