I have a painful ulcer sore in my mouth for four days now. It is on the left side toward the middle of my top and lower lip. I gargled with warm water with salt, used mouthwash, dabbed hydrogen peroxide on it but it doesn't seem to get any better. I am already at loss on how to get rid of it. It's so sore and it's so hard to eat.I have already developed two more small ones. What is the cause of this? How can I get rid of it?
Please help, thank you:-)