What Causes Swollen Lump With Foul Discharge In The Vagina?

i have a like a ball inside of my vagina it used to sit at the top , but that was two years ago i didnt get it treated or seen to becuase i was so young but now it has go worse and it is unpossible for me to have sex or do anything there is just no room , it is swollen and i suffer with bad disharge and smell