Recently I told my T that I wish a session hadn't happened and that I wanted it to go away! I felt so embarrassed. It was a session where I was in agony and was squirming around on the couch trying to hide.
Once I put the pillow in front of my face, but not for the whole session. Can you write what you can't say, at least to start out with, or wouldn't that help? Do you feel safe with your T? Can you ask her to help make it safer for you to talk about this subject?
Just suggestions for you. I'll be a pocket rider if you want, and I'll whisper "you can do it", "you can do it" over and over, in your ear!