I just did that myself. I wrote to my T first and then we spoke about it in a session. It was hard, I did feel embarrassed and nervous but I went away feeling better than ever. There really is such relief in getting something so honest and pressing off your chest and out in the open.
You can do it

You are not alone in how you feel, and your T has definitely heard this before from other people. It will be a great opportunity to talk about it and I'm sure your t will be accepting and understanding and help you feel comfortable. Good luck!