The last time JOHNNY BERRY saw his daughter, she was a happy, carefree 16-year-old, working at Burger King and making good grades in high school.

AMANDA BERRY's next 10 years would be spent chained up and gagged in a rundown house of horrors on Cleveland's Seymour Avenue, allegedly suffering a decade of brutal rapes and beatings at the hands of accused kidnapper ARIEL CASTRO.

"If I could get my hands on that monster Castro, I'd kill him myself!" Johnny, who lives in Elizabethton, Tenn., told The ENQUIRER in an exclusive interview. "I'd rip him to shreds!"

Prosecutors may seek the death penalty for Castro, but Johnny would rather see him rot behind bars.

"If I can't kill him, I don't want the state to execute him," he said. "That would be too easy for him.

"I want him in prison for the rest of his life. I know people in there who can make his life a living hell for what he did to Amanda. I want them to beat the s*** out of him every single day."

Johnny, who told The ENQUIRER he served time for sexual battery and aggravated assault, says he's turned his life around. Near-paralyzed from recent back surgery, his voice raspy from deadly pulmonary disease, the frail 53-year-old worries that he won't live long enough to see Amanda again or get to hug his 6-year-old granddaughter, Jocelyn, who was born during Amanda's captivity.

But he's grateful he's been able to speak to Amanda twice since her miracle escape on May 6.

"When she called me, her voice was the most beautiful sound I ever heard," Johnny recalled. "She said, 'Hi, Daddy. I'm still alive. I love you, love you, love you!' We were both crying…it was the happiest day of my life."

Amanda, now 27, is living with her sister Beth Serrano in Cleveland — and still suffering horribly from the effects of her captivity.

"Amanda's having a terrible time," Johnny said. "She's having nightmares every night, waking up screaming and crying, terrifed that Castro is coming after her, or that she's still a prisoner. She told me she's afraid her freedom is a dream and she's going to wake up to the horror of fnding out she is still a prisoner."

Heavily tattooed Johnny had a common-law marriage with Amanda's mother, Louwana Miller, who died in 2005. The pair broke up for good a month before their daughter was kidnapped.

"I can't say I was the best dad in the world," he admitted. "I feel a lot of guilt that I wasn't there for Amanda when she needed me.

"If I had only known where she was, I would have gotten a gun and gone over there and gotten her out myself, but we had no idea. It was like she just disappeared off the face of the earth."