Hi Sweepy, as for me I took a while before opening up again as I felt abandoned and didn't trust my current t. We started with lighter topics and the fact that she's never pushed me helped a lot. I considered never going too deep again but after a while I felt like I was depriving therapy of something and felt safe and was willing to really talk to t. You can ask her to give you some time to adjust and see how you feel with her, I think trust will come itself when you are ready.
I don't know if you like writing, but I usually forget the important things as soon as I step into t's office, especially when I'm tense or very tired. As others wrote, maybe you can write your thoughts, concerns and the things/topics you feel you can start with while you are quiet and alone. And you can bring it in and have a look at it with t.
Good job about the session by the way.