i am sorry to hear about your pain and suffering. I have this burning mouth problem too. I have to discontinue eating anything spicy, tomatoes, anything acidic. And stop drinking any soda. I have celiac disease and fibromyalgia. I found that gluten free diet has helped my overall health. And a big problem with my mouth burning all the time, was solved by stopping using any mint toothpaste or mouthwash. I have to use kid's Crest strawberry flavor toothpaste!
My dentist told me about discontinuing mint products She was right!!
I hope your problems ease up.