bleeding, gaping hole

i woke up this morning to find a bleeding, gaping hole in one of my teeth. i had it filled in high school [which was, trust me, a while ago], and the filling must have come out. i would consider the pain moderate, and nothing compared to a migraine. however, my aleve is starting to wear off, so i may be changing my mind soon. i HATE the dentist and haven't been for a check-up or anything in way too long. i'm worried they're going to find more cavities when they fix this one. don't have an appointment until tomorrow morning, so it could be an interesting night...