Oh man... well at least you have a date. Just hope you have lots of support ready to pamper you during the recovery time. I can't imagine & have no history of anyone I know of going through it, but from what I understand its a pretty common procedure for the doctors anyway, so hopefully there will be nothing abnormal about it & you will be better than ever afterward.
I had a tumor removed from my brainstem when I was in high school & they only made me wait about a week before determining they wanted that thing out & when the surgery was. Not sure which was worse, the tumor or the anticipation & worry before hand. Just remember this is something that is going to help you in the long run & HEY didn't you have twins TWICE? I'm sure that was scary... hopefully this will be a lot less, no midnight feedings or diaper poop!
Good luck & I hope you get a chance to relax now & then.