How can you get rid of canker sores?

yes i need to get rid of this little devil before friday. this is because im going to a concert and i want to be screaming my head off but i can bearily open my mouth a lot of the time. I can't even smile. Durning the night i think it bleeds, and during the day it swells. HELP ME! IT HURTS SOOOOO BAD! i put ice on it, and i used this sort of medicine where u swoosh it around in your mouth. I don't like to put baby numbs it or whatever its called because it is only temporary pain relief. i want some kind of thing to make the thing shrink!! please help.