Inside my cheek is a large (about 1/4" x 1/8") oblong sore (like a crater) that is extremely painful. I noticed it a few days ago because of the pain and the swelling (my cheek kept getting between my upper and lower teeth. Now it is more swollen, I can't eat without a great deal of pain. It hurts when I'm not even moving. It now hurts on the outside of my cheek and along the underside of my jaw which is now extremely sentitive to the touch and feels tingly all the way from my chin to just behind my ear. The inside of my cheek is not red and the sore does not have the appearance of a canker sore; instead, it just looks like a big open hole. Can you please help me figure out what this is and advise me what to do about it?