To what Cindy has said, I will add simply to eat well balanced meals, get regular healthy exercise, and if the surgeon recommends you cut back a few pounds, get going on that doing healthy eating and exercise.
Each surgeon has a different time table on quitting or reducing hormones and I would be sure you have given your surgeon and your normal health care team permission to talk to each other and provide records to each other from now up through the surgery and a month or two after to prevent writers cramp for signing releases for everything.
Find out what medical tests the surgeon needs and by when, and schedule them with your normal providers so you can have them to the surgeon on time. (I had one test result in the wrong time frame and had to pay extra to have it done the day before my surgery.) Quit smoking or abusing alcohol / drugs if that is an issue ASAP so it is not a last minute issue.
For the masturbation issue, have fun now and gain fond memories because it is going to change and be a little chaotic for a while after the surgery. At 11 months I am still re-mapping nerve wise and learning how I react to stimulation, and it does change.
