Duane "Dog" Chapman is opening up in a new interview about his final moments with his wife, Beth Chapman.

Beth Chapman died on June 26 at the age of 51 after battling Stage II throat cancer. Talking to Entertainment Tonight, Duane detailed her final moments, as well as the way she tried to prepare him for her death.

"For two to three years, she knew this might happen," he shares.

"So she would say, 'Who is going to sit next to you?' And I said, 'No one,'" he says tearfully. "'Big Daddy, you better not let another girl take my place.' I said, 'I won't.'"

Watch Duane Chapman's Full Interview With ET:

Despite her trying to prepare him, as her final moments were actually at hand, Chapman told his wife he wasn't going to let her die.

"The last few moments she said, 'Come in here right now, in the bathroom,'" he relates. "I went in and she said, 'Look at me.' And I said, 'Yeah, you're freaking beautiful, baby.' [And she said,] 'Look at me, Duane Chapman.' And I did, I always saw Beth, and she said, 'Please, let me go.'"

"And I didn't even make a decision, I almost said, 'I can't,'" he admits.

"Before I could say, 'Alright,' she couldn't breathe and I called the ambulance."

There was a public memorial for Beth Chapman in Hawaii on June 29, and Duane Chapman says he is still struggling very much with the reality of her death. He has her ashes, and it was her desire that he scatter part of them and keep part of them so that when he, too, is cremated, part of them can be together. But he has not yet been able to make himself scatter her ashes.

"I looked at it and I thought, 'I'm not gonna throw you, like, away," he says, his voice cracking. "I just throw you away and start over? I can't do that ... I haven't gotten past the place where I'm still putting a pillow where she was and covering it up ... and then I wake up in the middle of the night and see her, and it doesn't register that ain't her."

Though he's still in mourning, Chapman is determined to step up and handle everything that's still in front of him and make the decisions that have to be made. He's been working on a new show, Dog's Most Wanted.

"I have a lot of people who depend on me," he explains. "All my supervisors said, 'Dog, it's time you man up.' So I'm trying to man up."

A funeral for Beth Chapman is set to take place in Aurora, Colo., on Saturday (July 13). It will stream live on the Dog's Most Wanted Facebook page and on WGNAmerica.com.

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