- Jaycee Dugard was just 11 when she was abducted
- She gave birth to two children during her 18 years in captivity
- Her memoir, "A Stolen Life," is due in stores on Tuesday
- Dugard speaks exclusively to ABC News' Diane Sawyer
(CNN) -- U.S. kidnapping victim Jaycee Dugard, who gave birth to two children during her 18 years in captivity, said she did what she had to do to survive.
During a wide-ranging interview with ABC News' Diane Sawyer that aired on Sunday night, Dugard opened up about her experiences at the hands of her captors, Phillip and Nancy Garrido.
Dugard was just 11 years old when she was abducted in 1991 from the street in front of her South Lake Tahoe, California, home. The Garridos held her and her daughters in a hidden compound of sheds and tarpaulins until she was found in 2009.
Dugard is now 31 and working to build a new life, one in which she and her children are finally free.
"There's a switch that I had to shut off," she told Sawyer. "Just went someplace else."
"I can't imagine being beaten to death, you know? And you can't imagine being kidnapped and raped, you know? So, it's just, you just do what you have to do to survive."
Dugard recounted the first moment Phillip Garrido entered her life.
She was on her way to school, wearing her favorite shirt and a ring in the shape of a butterfly her mother had given her, ABC reported, when all of a sudden Dugard felt "tingly" and "numb."
Phillip had shocked her with a stun gun, the network said. The Garridos then put her in their car. She recalled Phillip laughing at one point, and telling his wife: "I can't believe we got away with it."
"It was like the most horrible moment of your life times 10," Dugard told ABC.
At first, she was handcuffed. Dugard said she tried not to cry because, with her hands behind her back, she couldn't wipe away her tears. Left on her face, they would itch, she said.
Dugard also recalled the first time she gave birth, in the backyard, at just 14 years old.
"I didn't know I was in labor," she said. "Then I saw her. She was beautiful. I felt like I wasn't alone anymore. (I) had somebody that was mine ... And I knew I could never let anything happen to her," she said.
Throughout her 18-year ordeal, Dugard managed to hold onto the ring her mother had given her and the hope that she would one day be reunited with her family, ABC reported.
"I wanted to see her more than anything," she said about her mother. "I would cry every day. (It was) hardest when I would think about her and what she was doing and then -- trying to convince myself she was better without me.
"Worried I'd forget what she looked like, or what she sounded like. Would she forget me?"
Her mother, Terry Probyn, also appeared in the ABC interview.
Last month, a judge sentenced Phillip Garrido to 431 years in prison after he pleaded guilty to one count of kidnapping and 12 counts of sexual assault. His wife Nancy Garrido got 36 years to life in prison for her role in the crimes, including kidnapping and one count of rape by force. The couple had pleaded guilty in late April in El Dorado Superior Court.
A statement from Dugard, read by her mother at the sentencing hearing, called the Garridos "evil" and described her kidnapping by them as a "sexual perversion."
During the ABC interview, she stressed she is moving on with her life. Dugard said she wants to study writing, the network reported.
She spoke out just days before her memoir, "A Stolen Life," is scheduled to be released. The book is due in stores on Tuesday.
"Why not look at it? Stare it down until it can't scare you anymore," Dugard said about her nearly two decades in captivity. "I didn't want there to be any more secrets."