It’s not a cold sore and it is getting bigger and sorer and tender to the touch and feels warm to the touch. It is inside my mouth on my upper lip
Try tea tree oil on a q tip 2-3 x’s daily, or once overnight & once after you brush your teeth in the morning. I hope this helps. If not, you may need to seek a doctor.
It could be an ulcer if you’ve recently had anything with a high acidity level. Too much orange juice or even eating a lot of tomatoes can cause this. Rinsing with salt water will help. If you haven’t had anything high in acidity content, then I would recommend seeing a dr.
I would not worry. If it came that quick it will go away soon. I get that sometimes, but usually when i eat raw garlic as it will burn the mouth bad. No worries.