I can imagine that it would be overwhelming to read the entire letter to her, or to have her read the entire letter while you are there.

Can you read one thing to her? I bet that you can. Maybe just one sentence, "I was kept in my room a lot." (or however you would say that, I'm just guessing from what you wrote).

You recognize that disclosing these things is a really big thing. It is and your recognition of that is a huge step. But how do you do this? Easy and tough. Just say one thing at one session (doesn't have to be your next one). Say it outloud to the mirror to practice every day for three days beforehand. Just one sentence.

Say just one thing. You don't ever have to say another thing again. Just see how she responds. I don't think she's going to be disgusted. I think she's going to be sad that you had to grow up like that, but she's going to think you are brave for saying it.

When you say it, you release at least some of its power over you.