Sore Tongue. Dentist Advise Taken. Biopsy Done And Diagnosed Yeast Infection. Mouthwash Used And Given Vitamin B 12, Folate. Advise?

I have had a sore tongue and the back bone kinda part of the jaw this has been hurting since March. I waited until June before I went to the dentist, he did not know so after a while I went to my Dr, he had no idea, went back to dentist and he gave me a referral to see a dry mouth person, I do have dry mouth from medication that I take. She did a biopsy and that said yeast infection, was put on mouth wash that she prescribed. That was in July, went back to my Dr he gave me a prescription for a mouth wash that cancer patients get. Then another time it was lidacan. I asked for a referral to an ENT, saw him earlier this month, he did a test for vitamins B 12, folate and iron. He also ordered a MRI which got the results last Friday with no abnormalities from that. I must say that Strawberry Llemonade hurt after I drank it and didn't think that it was that, I stay away from all things acidity now, still have pain. Anyway from the lab results my iron was either 22 or .22 so I am on iron now and low on folate but he didn't do anything about putting me folic acid, should I get folic acid? My B12 was high at 1500 but I get B12 shots once a month at the first of the month, they said since that was ok because of the shot. Do you think I am on the right track now? I still have some pain but I only started iron on Saturday. Thank you for anything you can do for me.