It's not so bad. Just tell them you want to make an appointment and when they ask what it's for say hormone replacement therapy. Can even write it down if you think you might panic, so then you can just read what it says on the paper :p
The appointment (and the paperwork) is really not bad at all. The worst part is the fear of the unknown. Once you're actually in there everybody's really nice. The only kinda weird part was how interested they were in my sexual orientation. As in they were a little TOO interested, but I think that's because of the STD information/services they offer. Also I wouldn't give them a straight answer (no pun intended). "It's evolving" is apparently not an acceptable orientation.
Anyways, you'll be fine. Take care!