(((((((((((Dustin))))))))))))))
Could it possibly be erotic transference? T's are trained to deal with feelings that their clients happen to express to them, so I think you should tell her. She's not going to fire you, but she might help you through all this stuff, that you can't make it through by yourself.

If you can't tell her flat out, perhaps writing it down and giving it to her? Hiding your feelings could be a stumbling block in therapy, and I don't think anyone wants that to happen.