Ok I just had the same thing and I went to the doctor...this post is for anyone else who has those same symptoms ( i looked this up before I went to the doctor and all I was seeing was really over the top like cancer and HPV etc.) But i went to the doctor and she said it's just an allergic reaction, for me I had just changed tooth pastes, but she said it can also have to do with changing your diet or medicines. Avoid foods with acidity and fried foods and It should go away in about a week. Hope this saves someone from the anxiety i got from looking it up!
Was your issue ever solved?
Seeing an oral pathologist or oral surgeon is advised.