You have a major problem with excessive masturbation. It's practically ruining your life. You have sought help by seeing a sex therapist. Before you begin your therapy session, your doctor insists that you do exactly what she says, otherwise there is no sense in treating you. She thinks the only way to curb your horny appetite is to wipe your brain of all other stimulation but her. You will only be allowed to masturbate in your sessions together. Looks like your addiction is going to come at a price because visits to her office are costly. This should help you cut back immediately. As an act of good faith, she allows you to masturbate for her in your first session.