In terms of things that had happened with my then-marriage counselor (regarding strong transference and other things, like fuzzy boundaries), I opened up to my current individual T very quickly. It was the third session, and I shared a whole bunch of stuff through tears. Then, I freaked out after session and emailed him because I was afraid I'd shared too much and he'd want to refer me on (mostly that he'd be afraid I'd become attached to him as well). It ended up being OK, and I think in a way it helped that I got some of that stuff out there early, even though it caused me some anxiety.

It also took me a lot less time than with my ex-T to share other things from my past with him. I felt like in a way, they were things I'd already shared with someone, so it made it a bit easier to share the next time. It may have also been that I felt very comfortable with him, while I never really did with ex-T (I did feel comfortable with ex-MC).

Do you think that part of it is saying things out loud? I'm wondering if it could help if you could type some of it out then share it with her over email, if she allows that? Or give it to her in session, but I know from experience how uncomfortable it can feel to sit there while the therapist is reading something. Could you also tell her that you need some help bringing up certain topics? I've also emailed my T the day before a session and said, "I need to talk about x thing tomorrow but am having trouble bringing it up. Could you help me talk about it?" And that has helped.

One other thing--do you necessarily need to share the details right now (both with trauma and your former T), or could you just give her something more general and fill in more details later?