You need some pain killers. You could call your dentist and explain that the local A. isn't working and you insist on proper care. See if he will write a script earlier in the day OR ask if he has any oxycodone (either by itself or in Percocet combined with tylenol) at his office. If he does, take at least 2 (10mg).
At 10mg you will still feel pain but you won't care as much. To really feel no pain I think around 15-20 mg is necessary. Having an empty stomach will increase the effects.
Rei's suggestion of valium isn't bad for relaxation and stopping anxiety beforehand but there is zero analygesia and pain is still really annoying on benzo's (valium, ativan, klonapin...).
Or the Doc may choose a weaker version like Vicodin (hydrocodone) or Tylenol with codine. Vicodin is ok but the Ty w/ codine is extremely weak.
It bugs me that MDs are withholding pain meds to ordinary people all over the world now because of lawsuits and things.