I bit my lip yesterday and the swelling hasnt gone down?

I was super bored yesterday in school so i started biting my lip. when i was at my boyfriends house it started swelling up. so by the time i got home at 7 it was HUGE. so i figured id just go to bed and sleep it off. well, now its 4:32 the next morning and the swelling is still there. i had told my mom last night and shes a nurse and all she said was "then stop biting it " which wasnt much help and now im kind of scared. im gonna stay home today because im not really feeling like going to school with a fat lip. what can i doV