Andrew,
Chin up (pun sort of intended)... Been there done that like 25 years ago. The going under part is not really all that bad, pretty much like taking a nap - nothing to worry about... unless perhaps you get Focus' dentist.
In my case, I woke up during the proceedure and despite finding my surgeon with his knee on my chest pulling for all his worth at my tooth, that did not concern me, as I was paying attention to the well endowed assistant in his employ. She noticed me noticing her and in moments I was out again.
Just follow all the instructions you are given as regards care... From everything I've heard about dry sockets, you don't want that to happen. It will also help if you have a driver to take you home and someone at home to keep track of you and your pain pills - day 1 and day 2, I'm sorry to say, you will need those.
As things go, it is not as bad as all that, so just hang in there and in about a week or so you should be feeling quite okay.
-Commerce