Hi, I was also afraid of dentists...until I found a gentle dentist. They even offered a medication to take to lower your anxiety...you didn't "go to sleep" you were just very relaxed. Is there someone in your area that does that, or do you have a med that could help in the same way??
I would wait until tomorrow...just remember to take some deep breaths and know that you can tell them to stop at any time. It also helps to tell them that you have severe anxiety and they will be so much more sympathetic to you. It's amazing really how empathic people are when you open up to them.
Good luck,
Sherril