It's really important to feel safe with whoever is doing the exam. I strongly suggest that you talk to your GP about who the best person is for you. Then, if you can, arrange an initial consult without an exam.
For the exam itself, if it helps to have someone with you, arrange it. If you need to have your iPod playing at full blast, take it along. If you need sedation, ask for it. If you prefer your doc to be a particular gender, only consider people of that gender.
I once saw a slogan, aimed at transmen, something like "Real men get Pap Smears." Nice idea, much harder in practice. You do what you have to do to take care of yourself. Just keep thinking, "Hysto, hysto, hysto!"