I read your message half an hour after you posted it. I presume you're probably in the doctor's office as I write. Good luck. I found it very difficult to come out to my physician. He was fine with it, although a little clueless about my trans husband. But the work I did by coming out a couple of years ago (after reading on SF how important it is) prepared him for the night two weeks ago when he was on call and saw Charley in the emergency room. The doctor never batted an eye and treated Charley as the man he is, concerned about his heart and leaving the rest to us and our relationship.
The worst that can happen has already happened to you once. But the fact that you feel he is the best doctor you have ever had tells me that he'll be fine with knowing the "whole" you. He may have already guessed. Let us know how it goes.
When you can transform the war and violence in yourself, then you can truly begin to help others find peace. Thich Nhat Hanh