I will add another to journalling. Even writing down any questions you have, any insights about yourself, might help. I actually sometimes write letters to my T about things I can't express verbally, but he needs to know.

I couldn't jump into everything right away with my T, it took us quite a while before I could discuss pretty much everything with him, without turning into a sobbing (or yelling ) mess. Maybe tell your T what you think you can't/aren't comfortable talking about right now, then say what you do want to talk about.