Your mother sounds like a very difficult person. She should NOT be blaming you at all for the issues you are going through. She should be concerned about you right now, and not herself. I'm sorry she is being manipulative towards you.

I hope that during that one week of therapy you have alone, your T will already have put together the pieces of the puzzle, and caught on how your mother is manipulating the situation. I also hope you'll be able to tell the T what your mother is doing.

May I ask how old you are? I'm just thinking, it might be very beneficial to move out of the house, and gain the independence that you deserve.