Granite, you are doing this in therapy for very good reasons. This noise in your head is triggering. Your past is most likely being triggered up as you sit there in front of your therapist in therapy feeling the pressure to talk. The only way that I see you getting out of this is to figure out what is going on with you and to work with yourself to get out. You are afraid to talk in therapy for very good reasons. You mention in this post that you don't want your T to leave you. Do you think/feel that speaking in therapy will make her leave you? When you have this fear of speaking in therapy what is it reminding you of in your past?