Carmen, I to have been a second guesser, worrier & deprived myself of sleep also. Sooner or later, you just have to say to yourself, I've looked at everything, decided this is what I'm going to do & then treat yourself to a Tylenol PM to help you still your mind.
I read somewhere that eventually it all comes down to trust, Trust in yourself, your Dr, & your own decision making ability.
Best of Luck with your surgery.