This is a serious breach of confidentiality. Your T has no idea what your friend will do with the information he gives her (if she's not much of a friend whatever he tells her could be used to intentionally hurt you). I hope for your sake that she really is a friend and would tell no one. Your T and friend have no right to discuss you. I'm sorry this happened to you, I'm sure you are devastated at the lack of respect you've been shown.