Thanks everyone for sharing your advice and especially your experience.

I did go to T today. And he did want to talk about the e-mail. I told him I COULD NOT talk about it. In the end, we briefly talked about it a little tiny bit, but not about the hard thing that I regretted sending to him. About 20 minutes into the session, I announced "well, I can't talk about that e-mail, so I think I'll just leave now". He told me "I don't think it would be a good idea for you to leave just yet"....so I stayed and we talked, but more about what I was feeling right then and what was happening in the room. I WANTED to dissociate and get my mind OUT OF THERE, but I was weirdly present the whole time. Usually, I just drift away when it's hard and there's not a lot I can do about it. I told him that, and he talked about how strong I was to be able to sit there and tolerate what was going on. I actually did feel strong being able to do that - but it gave me a raging headache.

Anyhow, I think I'm glad I went. I'm not sure how I feel right now. But I do appreciate everyone's help. Thanks.