Tell your surgeon, and he or she will decide. For me, they shot me up with valium before I even left my room, and I was pretty much asleep before they even got me into the operating room.
there are a lot of different meds that could be used...the best ones to use are whatever your doctor gives you. there are too many variables in this type of situation for anyone to say one is better than another. i would just call who ever is doing the surgery and explain to them your anxiety level now and ask that they give you something to take prior to surgery. it's not at all uncommon. otherwise, meditation and relaxation excercises might help...but then again, might not.