I definitely have had trust issues. I haven't always been honest with therapists, and I NEVER talked about gender and sexuality issues. My penultimate therapist wasn't a good fit, and I had other reservations about his motives. My last therapist messed with my head--probably an honest mistake, but it felt like he was intentionally screwing with me. After these experiences, I vowed that I would never see another therapist as long as I lived.
Then I came out this summer. It took me only a couple of weeks to realize that I had to go face-to-face again. I made my appointment. The first day I had to come in early and fill out some forms about my background. I didn't fill out the sections about my family and my previous experiences with therapy. It would have taken more than a couple of lines, anyway, but I just didn't want to deal with those things.
After the initial phone interview and the first visit, though, I knew that I could work with this man, even if I was scared out of my freaking gourd. He was a good fit, and he did everything exactly right. I realized that I needed to fill in the gaps in my history, so I wrote it all out and gave it to him the next time I came in. I'm glad I did--I mean, I was a little embarrassed about some of the things I had written, but it was all true, and it really helped to take stock that way. And I didn't have to stammer and stumble my way through it in a session. It acted like an icebreaker, really. I told him a lot of very personal, sometimes painful stuff in my letter, and I was not struck by lightning.
I really think that you should consider giving your therapist the letter before you go in. Explain why. Explain that you are concerned that you'll be evasive or deceptive if you talk things out and that you might even clam up altogether. I think he'll appreciate your candor, and you'll be helping him to help you better.
I've had maybe half a dozen sessions so far. And most of what I've talked about has been peripheral. I'm still getting used to talking about my most personal stuff--and I've been in therapy several times before! The thing is, he knows that I'm only skirting the issues, and he knows that it will take time for me to get there. That's okay. He is giving me time to acclimate. So we talk about lots of things. I have never lied, though. I made a sort of pact with myself that I could leave things out until I felt more comfortable with them, but I could not lie. I've held to that agreement, and I think I'll continue to do so. You're obviously in a different place, but if I can do it...well, that should give hope to you.
Outside of therapy, I've been working very hard in the past month to find my courage and get used to the idea of confiding in a professional who was (let's face it) a complete stranger to me only a month ago. But I almost feel as if a miracle has occurred here. I thought I was the last person who would ever go through therapy again, I have been suppressing my identity for years, and I've been truly terrified of opening up to anyone. But I got lucky. I was ready to start overcoming my reservations, and I found someone who is truly gifted in his profession.
I trust my therapist now. I mean, I REALLY trust him. I hope you can find that, too.