I have a canker sore in my mouth !HELPPP?

I never knew it was called a canker sore,lol. i thought it was a cold sore. but anyways ! , i have a canker sore and it is really starting to bug me, even though i have it for like 3 days. It started of small, and it became a little big. then bigger. I hate having canker sores, i tried using carmex but it never went away. does salt work ?