history: I hate going to the dentist. I have an appointment coming up and I don't want to go. I have a tooth that has been hurting me for awhile and I have already put it off. I have a dentist appointment next week. I hate going to the dentist. I don't want to go. I went through that for like 5 years.  Ended up finally going and they've made a lot of advances in comfort since I last went before that.
current: I have a tooth that has been bothering me and I've already put this off for so long.
next: Yeah, you should definitely bite the bullet (metaphorically).  It'll only get worse from here if you don't do anything, and it probably won't be as bad as you worry.