It sounds like your mother is drawn in several directions at once. She seems to want to have a better relationship with you. However, she also wants to avoid blame for the past. She wants it all to be the fault of others.

Why do you suppose that she is critical of you, and hurtful to you, even now?

No wonder it is so hard to trust her. Even now she is hurtful of you, and she does not seem sufficiently open to, and compassionate about, hearing your pain and perspective about the past.

At the same time, though, it sounds like you are having difficulty trusting your T. You trust her, I gather, as a person, but maybe you find it hard to trust her skill as a therapist. You find it hard to trust that she will see what you see about your mother. Perhaps you worry that T's feminist stance could blind her to the possibility that women, mothers can indeed be unloving, abusive, hurtful, negligent. That not everything can be blamed on men.

I'm really sorry that you must wait so long to speak to T. Perhaps you could write out your thoughts and concerns, though, in some detail? In my mind, this would help you identify and express your complex feelings about the session, your mother, and your T.