I had a simular issue. I had been ill, and progessively becoming worse. This went on for around six months. During the last two months, I became so sick that I lost around twenty pounds. I was like you as far as eating, except I had converted on a veggen diet about two years previous to my symptoms. My syptoms were at first occasional nausea, became vommiting and then later dehydration and projectial vomiting. All the test showed that everything in my digestive system was fine. Then this extreamly wonderful Dr. read an article about hyperactive gallbladders. It said that people with hyperactive gall bladders could experience these symptom. At this point he suggested that I have my gall bladder removed. I had it removed and slowly the nausea went away and I started feeling so much better. All I can say that if the doctors can not find out the issue with you, keep looking until you do find the answer. Good Luck to you.

The above is an indivials opinion and is not intended as Medical advise.