Peace,
The last thing I said to my wife, daughter and son just before they wheeled me into surgery was, "Now I've got the easy part, I'll be asleep through this, you guys have to wait it out". Trust me, 3 hours (mine) or 12 hours (yours) makes no difference, you'll wake up with plenty of pain medication in you. Never hesitate to ask for more if you need it. I think the most asked question I got from my nurses was "are you in any pain?".
Good luck, you'll do fine.
Jerry