I'll answer your question as to how I do it. Years ago, I didn't. I was like you, though I could talk about day to day stuff that wasn't so important. But T would ask how I feel about something, especially about her, and I would sit there, silent. I would say "I don't know" a lot. So I would be able to tell her facts, but not feelings. I showed her some of my journal after a few years of seeing her. It was never easy to talk.
I saw other Ts and I got better each time. I'm not sure why. But I'll tell you how this T, more than the others, makes it easier to be so honest and tell her what I feel about her, especially.
1. She does breathing and relaxation exercises with me first because she knows I'm anxious.
2. I've asked her a number of times if it's okay to tell her anything, and she says yes in a way I know she means it.
3. She's very non-threatening and doesn't act better than me. She acts like we're in this together.
4. With IFS (Internal Family Systems) you deal with parts of your personality. She says we are curious about a part, not judging it. She tells me that a lot.
5. I close my eyes and then I don't have to see her looking at me. It makes it easier to talk, though I know for many that would make it harder.
6. She says "good" when I tell her how I'm feeling.
7. She likes me, and I know it.
All of the above enables me to tell her. Plus, something in me knows that I have a need to unburden myself. It's worse for me if I don't tell. I'm miserable then. There's stuff inside of me wanting to come out so I let it. I don't have a sick, panic feeling so much anymore but I'm still anxious and embarrassed like I posted.
What if you asked T how she will keep you safe if you "explode"? If you feel out-of-control when you start talking? She probably knows what to do. Maybe you are worried too much about what might happen. You used to scream and be out-of-control? With her or someone else? What about saying "I feel like screaming?" Maybe you could hit a pillow instead?
I like the art therapy. Maybe if you continue with that for awhile? Can you do both? Give her the list, and do the art stuff?