Ive had this real bad canker sore on my upper lip right where my tongue hits. Everytime I eat/drink it hurts extremely bad. I took anti-biotics, I tried gargling the salt water, and I used canker sore medicine on it. Ive had this for at least a week now. The medicine does not help. It says it last for hours and it did at first. The pain kept coming back and it got bigger and looks worse and feels worse. When I put the medicine on it now it lasts for like 5 minutes and I keep having to put more on. The problem is it says to avoid eating/drinking for 1 hour after putting it on...Someone please help me and tell me what I need to do...Thanks!