There are so many different symptoms for when you get into gluten. But from what you described, it is exactly what happens to me. Before I was diagnosed with Celiac Disease I had been sick with vomitting/diarhea for about
8 weeks. When that finally stopped, everytime I ate my stomach would burn so bad, and nothing would help. Not even prescript
ion meds. I put up with it for about
3 months and finally couldn't take it anymore so I went back to the gastro dr and described my symptoms to him and to my surprise he said he thought I had Celiac. I was expecting him to say I had an ulcer. But since none of the antacids were working he didn't think it was an ulcer.
If I get into gluten now my symptoms are much worse than they were during that 3 months before I was diagnosed. Even today I did something stupid that got me into gluten. My daughter got an order of crazy bread from Little Ceasars and she also had a fountain drink. I had a fountain drink as well, in the same type of cup. When we got home we carried in our drinks, then carried in the groceries. We didn't know whose cup was whose. I drink diet, she doesnt'. So without thinking I took a drink from one of the cups. It was hers. But it also had gluten all over the straw from her drinking while she was eating the crazy bread. My stomach has hurt ever since.
It may take you longer than just a couple weeks to notice a difference. You may also have a problem with milk/dairy or other things. Several months into doing gluten free I had to stop drinking milk and eating ice cream. It caused major stomach upset. So you may try that as well.
Hope you start feeling better soon.