What if the therapist or psychologist you are seeing has a borderline personality disorder?

Answer 1

If the therapists own mental health is having an impact on you and you have noticed that they are not well themselves, then you should change therapists. It may seem harsh and you should do so calmly and kindly - maybe even try to talk to the therapists boss or whatever governing body they may be regulated by (APA, BPS etc) to check that they themselves are getting the help that they need. Put simply the therapist may be transferring their own problems onto you and thus neither helping you nor dealing with their own issues.