After Hough's parents divorced when she was 10 she decided to move from South Jordan, Utah, to London with her brother Derek and study dance at London's Italia Conti Academy of the Arts.
"While I was in London, I was abused, mentally, physically, everything," she tells the magazine.
"I was 10 years old looking like I was 28, being a very sensual dancer," Hough explains. "I was a tormented little kid who had to put on this sexy facade because that was my job and my life. But my heart was the same, and I was this innocent little girl. I wanted so much love."
The abuse got worse "when I started hitting puberty, when I started becoming a woman and stopped being a little girl," she says.
But Hough, who has been dating Ryan Seacrest for over two years, declined to give any other details on her painful experience. "I'm a very forgiving person, and I don't want to hurt anybody," she explains. "What's past is past."
The actress did fight hard to get her part in the Lasse Hallstrom-directed film adaptation of Nicholas Sparks' bestseller, which opens in theaters Feb. 14. Safe Haven tells the story of Katie, who eventually falls in love with a widower, after escaping an abusive relationship with an ex-boyfriend.
Hough's costar/love interest Josh Duhamel urged the director to cast her. "I told Lasse, 'There is a sadness in that room, something more complicated that the character needed to have," he says. "And that's what she has.'"