I'd be sceptical that his therapist actually told him those things about you.
Any therapist worth their salt will concentrate on the problems that their client is presenting with, not try and blame the partner. Any therapist worth their salt will realise that it takes 'two to tango' and is more likely to be looking at the dynamics between you, rather than scapegoating - which is a typical part of his paranoid personality disorder.
To put it another way - if this were a court of law, do you think there would be any difficulty in demonstrating that someone who was "bipolar, paranoid personality disorder, and drug and alcohol dependent" might not be the most reliable of witnesses? I get that he's very manipulative, but therapists are trained to see beyond this - and I suspect that all this negative stuff that she's supposedly come out with is yet more manipulation on his part towards you.
If he wants you to go, you can always give it a try but keep an open mind. I'm guessing that if you attend and issues are clarified and worked on, it won't be long before he leaves again because the therapist is "bullying" him.