I am so sorry this happened to you
You have been through so much and now this.
It actually sounds as though she encouraged it, knowing you had some erotic transference but started hugging you, very unproffesssional. She should have not hugged you!
I think once she received a letter from you, she got scared because once it's written down it means it's official. She probably thought that you could put a complaint in about her. I think maybe she was protecting herself and you since it was causing you a lot of distress with these feelings. I know it's hard now but I think it is best for you. Maybe you could find a male therapist?