trans | Therapist anxiety!

I'm a M2F and I have my first appointment with a therapist tomorrow, and I'm getting pretty nervous! I've never been to a therapist at all in my life, so that's bad enough! I think my biggest worry is that I'm going to be told I'm not truly TS, which scares me. Probably won't happen, but it's still a concern. Anyone have any advice to at least calm my nerves a bit? Thanks everyone!