From the time she ran away from home at age 12, the odds were against Carissa Phelps.
Living on the streets of Fresno, Calif., surviving any way she could, she was preyed upon by men who said they would take care her but often ended up using her.
"It's the streets," Phelps said. "If you see any guys, you go with them, you hang out. You're a runaway."
By age 13, she was fully immersed in a world of prostitution, violence, rape and homelessness.
Amazingly though, Phelps fought back and went on to graduate from UCLA's law school and business school with an MBA degree.
Phelps is telling her story in a new documentary called "Carissa," with the help of Academy-Award-winning filmmaker David Guggenheim, director of "An Inconvenient Truth."
Find out about helping homeless teens at www.homelessyouthamongus.org.
In the film, she bravely relives the dark memories of her past. One of 11 children, Phelps initially ran away from an abusive stepfather and a mother who didn't protect her.
"I had to leave home," Phelps told "Good Morning America." "It was, it was abusive and we were too many kids in one house. Ten brothers and sisters and my stepdad was beating up my brothers and trying to exploit my sister, and I just thought, I'm gonna get out of here before he does it to me."
She moved around from group homes to juvenile hall to seedy hotels as a teen prostitute.
"I was a target to be sexually exploited," she said. "They very much understand your psychology and that you're vulnerable and they exploit you, very slowly tell you things like I love you and I'll be your boyfriend, and they're 24 years old and you're 12, or they're 40 and you're 12."
But luckily, Phelps found mentors who helped her realize her potential and pursue it.
She credits Ron Jenkins, a former Fresno State football player who became a counselor at Fresno juvenile hall, with saving her life.
Jenkins saw how smart Phelps was and told her getting an education would help her change her life.
Phelps later had a high school math teacher named Mrs. Weggeman who also encouraged her to achieve her goals.
"I was looking for approval and attention and love, and there were people that were willing to do that, that were in positions like teachers and counselors," Phelps said. "And through bits and pieces of that, I pieced together a family that's still intact today."
Phelps went on to law school, hoping as a lawyer she could change the kind of situations she came from, but she eventually decided she could make more a difference with a degree in business.
"Going to business school was kind of my wake-up call of, how do you actually get things to change in America. And I needed the tools in business school I think, to do that," she said.
Phelps recently resigned from a well-paying, coveted position in a private equity firm in order to speak out against youth homelessness.
"I know that this is gonna be carried forward and that I'm gonna be a leader in this. I have to be," she said.
Phelps said even when she was on the streets at 12, her fantasy was to get out of that situation and tell other people how she did, so in a way she believes the film is part of fulfilling her destiny.
"I was always wishing that I had been part of the civil rights movement, part of something that was bigger than me," she said. "And now with my story, with coming out and seeing the problem the way it is right now, I can do that for people that are voiceless, people that are homeless. Kids that are just invisible I can stand up and fight for them and it's, it's a wonderful feeling."