Please subscribe me some medicines that would help. If it is herpes, then acylovir or equivalent would help. If it is lupus or a connective tissue disorder, then that problem would have to be addressed, so work on the causal diagnosis first. There are topical medications that help the pain. Liquid benadryl swish and spit can help and there are topical gels available at your pharmacy that help.
Dentists sometimes can help with topical covering to decrease the pain.
The area appears unusually red in color, has no appearance of a rash or other changes in surface appearance. However, I can feel a slight texture with my tongue that I can best describe as fuzzy or rough. The best comparison I can make is that of rubbing one's finger across coarse sandpaper. Most of the infective causes are painful, which you are not describing. I don't know if you smoke or how old you are.