I think that's strong of you to consider that maybe it's you. Well, from reading here on PC for a while now, I think it's common that people feel that way in therapy. It sounds like you understand that it's a therapy thing, and not just you.

I feel dumb, silly, embarrassed about the reasons I'm going to t- stuff I gave as the reason for being there at first. He hasn't asked me to talk about it again a lot except last time, and I didn't manage to say much. Sometimes I semi- think I should quit because my issues aren't all that real or serious or acceptable, but then I remember that there WAS a reason I wanted to go and it's still there. It doesn't matter if my issues are as serious or acceptable as other people's issues- it can still be a good idea to work on them. Besides I've quit a zillion times before and just kept wondering if I should try again/ should have tried harder, etc., so might as well stick with it.

I think it takes time to get comfortable with your t, same as with any person, except it's harder since in t the reason for being there is to talk about stuff that wouldn't be comfortable to tell someone when you first meet them. So, maybe take your time and see how it goes?