Just when I thought nothing in Hollywood could shock me, Mackenzie Phillips drops a bombshell. The 49-year-old troubled actress appears on Oprah Wednesday to promote her new autobiography, High on Arrival, and took the opportunity to reveal that her dad, John Phillips of the Mamas and Papas shot her up with heroin for the first time, and forced a sexual relationship upon her which lasted for years. ….. she was already a star playing a...