She broke the law when she talked to your GP without your permission. Plain and simple. For me this would be the red line where I wouldn't even consider to work things out with her. In case of breaching confidentiality there is nothing to "work out". Not only would I terminate therapy immediately, but I would also report her to her licensing board. If this was just about her unprofessional behavior like cutting sessions short or starting late and the fact that she doesn't seem to be doing a good job as a therapist, it'd make sense to talk with her and to see if those issues could be resolved. But when the therapist does something illegal, especially when it's a breach of confidentiality, there is nothing for me to discuss with them. I don't understand how it's possible to trust a therapist who communicates information about you to someone without your permission. This very action is a prove that the therapist doesn't respect your privacy and, therefore, untrustworthy. This is just basic common sense and I am grounded enough to see this simple reality for what it is.