I had been through therapy a number of times before for non-trans things. But talking to my gender therapist for the first time may well be the scariest thing I have ever done in my life. I was at the end of my rope after repressing for years. I figured that if he wasn't the right one, I wouldn't have the guts to find someone else. All or nothing.
I guess I'll never find out what I would have done; everything worked out fine. He understood, and he did his best to put me at ease.
He has never failed me. Now I would trust him with my life. In a way, I already have.
Your therapist might not turn out to be a good fit for you, but of course you realize that if you don't go, you will never find out, and you'll never transition. Just keep telling yourself that this is the first big step to transition. And remember that the therapist WANTS you to feel safe.
I must be one of the biggest chickens in the known universe, but I did it. If I can do it, I know that you can. And it will get easier and easier. When you go in there for the first time, think of all of us at Susan's. We're behind you all the way.
Good vibes to you. Let us know how it goes. We're rooting for you.