I have this sore, for lack of a better term, on the inside of my lower lip. It's right in front of my right canine tooth. I don't know what it could be. It's not any type of cold sore that I know of. I have never had a cold sore so I don't know if there's any that occur on the inside of the mouth. The only guess I can come up with as to what it might be is a sore from biting myself. I sometimes chew the insides of my mouth without realizing it and get sores, but it's usually on the insides of the cheeks. It's been there for about four days, though, and it's not going away. It's starting to hurt when I eat and it's just really bothersome. Is that what this is? Is there anything I can do to make it go away?