Owww...I can't say I have experienced anything like that, but I feel really sorry for you about that. Especially since you have put-up with the pain for a long time. I hope your tooth gets better!
Do you mean a root canal?
I have the same problem, my front tooth was chipped when I was younger and I had a cap fitted when I was 16. However, nearly 10 years down the line and drinking hot/cold stuff would be painfull. I didn't know if it was my capped tooth or the one just next to it. Anyway, the dentist decided to do a root canal on my un-capped tooth - it was erm, how can I put this, hmm, err, 'ify'.
Unluckily for me though, the pain is still there albeit a subsided pain, so i'm going to leave it. Otherwise i'd had to have my cap removed and another root canal done >.<
I ****ed up the nerve in my front tooth about five years ago (by hitting it on pebbles whilst drunk), and it all but died. I know that the pain when I drink tea sometimes, which is caused by the remaining life in the nerve, is far less pleasant than the highly noticable numbness there most of the time. Having no nerve sensation isn't nice, but it's not really the end of the world. The only problem you may have is lack of bloodflow making your tooth look purple, but I'm sure having a cap would remedy that.
if you managed to knock off part of your tooth, what the heck did her shoulder look like afterwards??