Janet Jackson, in an interview with Today's Meredith Vieira, confesses that she struggled violently with her appearance in her 20s. "I would literally bang my head up against the wall because I didn't feel attractive," she said. "There was a lot of pain in my life. But I did. I felt very unattractive." Her brothers' nicknames for her included "horse," "pig," "cow," and "slaughter-hog," which she knew they used affectionately but still had trouble brushing off. Jackson also talked about her relationship with her father, Joe. "He said, 'I'm Joseph to you. You do not call me dad.' That affects you as a kid ... I know my father loves me. He just has a very, very different way of showing it." The interview with Jackson, who’s promoting a new memoir, airs Friday.