Hi,
I'm very sorry to hear what you went through . I commend you for having the courage to stand up and take him to court. I'm a mom and I can't imagine not sticking up for my daughter. It I was in her shoes I swear I would have killed him. I think the fact that your mother didn't support you proves that she is somehow a mentally sick person.
Forgiveness is a tricky emotion and difficult to do sometimes. If you never forgive her - no one would blame you. I think what the therapists was getting at was that forgiveness would lift the burden from you. Forgiveness is a gift we give ourselves and it doesn't mean we condone the wrong doer. If she is remorseful about how she acted , then I would say yes - forgive her. But she is still living with him so I don't think that's the case. Maybe one day she'll regret how she acted or should I say "didn't act".
I just wouldn't worry about it and instead form other attachments to other family members and friends. They can support you through the miles stones. No matter what you did the right thing. Take care and don't let them ruin your life. You're obviously a fighter and a survivor so I think you're gonna do fine.