I have a ball of painful gum tissue does anybody know?

sorry for bad title grammar. I have a ball of gum tissue on my wisdom tooth on the bottom left side of my jaw. its about the size of a small bean. Its a little painful left alone and very painful when pressure is applied to it. Its located on the right wall my wisdom tooth which is all the way at the back of my jaw. I cant even put my teeth together to smile cause it's in the way. Anyone know what it's called?