I have the same sort of problems with mouth/tongue pain. It has never gone away and my cancer was 2001. Soda, toothpaste, mouthwash, fruit, alcohol all hurt. I never know if something will be painful until I taste a bit and my mouth seems as though it is on fire. There seems to be no help that I can find for this. I carry Anbesol Maximum liquid and q tips in my purse, have it in my nightstand, and in the bathroom. It's the only thing that helps, even though it is very temporary and I have to reapply often. I have never heard of anyone else having this problem. Good luck to you.