If you are in the US, you could try looking up doctors on Angie's List or one of the other review sites. A nice doctor makes a big difference. You could also make an appointment with a doctor to ask for certain things to be done, without a full physical. I have had a blood workup done, for example, without a full physical.

I had a lot of doctor-related trauma in my childhood, so I relate a lot to this question. Another thing that has helped me a lot has been yoga - thought at first it was very difficult for me to tolerate because when I started for the first few times, sitting on that mat reminded me of sitting on an exam table. Getting over that has been really helpful to me, and has made dealing with doctors easier.