<<Disclaimer: Verify this information before applying it to your situation.>>

Wow!  All I can say is that I had mouth ulcers until diagnosed with celiac
disease (at age 60) but the ulcers virtually went away with the diet.  How
well are you sticking to the diet?  Little things like eating out, licking
envelopes, red wine, etc. etc. make a difference.  My advice, as far as
gluten is concerned, is to get every book and internet source you can and
make absolutely certain you are 100% on the diet.  Good luck.