I think being vulnerable in therapy is not a good idea. I think clients often get lulled into a false sense of security that the therapist actually cares beyond what is required by their professional role and many of them are extremely unprofessional and have no idea the harm they cause to clients. I think if you feel you have to go to therapy then never, ever fully trust a therapist. They don't care as much about you as you do about them, in general.