A therapist is a good place to start. Certain kinds of therapy can be effective for borderline personality disorder. So it sounds like your mom is on the right track, but it would be good if there was openness surrounding the appointment. It does not feel good to be "tricked" into doing anything. If you are looking for a diagnosis, a therapist can do that. For personality disorders, though, therapists often like to get to know you and have quite a few sessions before making such a diagnosis. It is very typical not to diagnose a personality disorder at the first meeting. You can get help without having an official diagnosis in your chart, so don't worry about that. Plus, you can be treated for your anxiety and depression symptoms. A diagnosis of borderline personality disorder in your chart can be stigmatizing, so please don't rush to achieve this.