You really have 2 problems that need to be solved - 1)How to get over any problems if you do need an exam from a male doctor 2)How to go to a female doctor which you will enjoy without calling attention to your fetish.
For the first problem, you need to separate your legitimate medical needs from any enjoyment you get from your fetish. If you have a known medical problem that needs to be dealt with, some times the best doctor will be a man. In those cases you just need to keep your mind on getting the best care. For appointments that are more routine, and you can choose a doctor more casually, then select a female.
When it comes to your behavior with a female doctor, what you can probably just say is that you are shy, and doctors make you nervous, and male doctors some times seem more intimidating (like a father figure). This will probably be an explanation the female doctor will understand, and it can also be an explanation if your actions seem excited or nervous. You might be excited, but the doctor will not be bothered because she thinks you are just nervous.
I used to be nervous with any doctor, but the more exams you have, with male or female, the more comfortable you become. I have had so many now with both that I can enjoy being examined by a female, but am not uncomfortable if I need to be examined by a male either. Good luck.