I think it's very common, and also a bit heart-breaking, that people who have been abused feel ashamed as if they were in some way at fault for the abuse, though of course they were not. Your T will understand this and will help you to see that it is in no way your fault and you are not gross or bad or anything like that.

I'm sorry you have this hanging over your head... do you have out of session contact with your T? Maybe you could email her that you need to tell her some things on Friday and you're afraid she will judge you or disbelieve you. I think she could reassure you that that's not going to happen.