The 41-year-old former glamour model feels "disgusting" about cheating on her ex-fiance and will always feel bad about the way her on/off romance with the fitness instructor came to an end.
Speaking on Monday's (03.05.20) 'Katie Price: My Crazy Life special, she said: "I've hurt Kris, I cheated on the guy. I feel disgusting for doing it.
"He will be one of the biggest regrets of my life."
The episode saw Katie - who has Harvey, 17, with former boyfriend Dwight Yorke, Junior, 14, and Princess, 12, with first husband Peter Andre and Jett, six, and Bunny, five, with third husband Kieran Hayler - decide to check into rehab for severe stress, and she reflected on how she turned to drugs and alcohol to cope as her life spiralled out of control.
She said: "I mean, there's only so much I can take as a human being. Traumas from the exes, the media giving me a hard time with constant bulls**t stories. I've had two dogs that have died, I even got blamed for that by the press.
"It got to the point where I literally can't talk to anyone. My mum is terminally ill, I don't want to stress her out. Yeah, I turned to coke and I turned to drink."
And Katie admitted her decision to seek help had been a long time coming.
She added: "I need to get myself well for Harvey and the kids. I think this is something which has been brewing for a while."
After a month in the clinic, the 'Loose Women' star decided to check into a hotel because she couldn't face going home as the house reminded her of the partying she was trying to leave behind.
She said: "Because my head was so numb with stuff, my reaction was 'Oh just another thing, just another thing,' which wasn't normal to act like, Just no emotion.
"So that's why I turned to something to escape from that, and mine ended up being the coke. This is why I can't go back to my house, the times I've done coke there, all the parties there."
But Katie insisted she felt stronger than ever and was looking forward to turning over a new leaf.
She said: "A month later, I've learned to be more assertive, I'm back in control. It's taught me that yeah you may have problems but it's taught me how to cope with things.
"It's the best thing I have ever done. I'm not going to be a product of people. My name's Katie Price: human being, mother of five, loves her job, loves her work, and I hope you enjoy watching the new Katie Price reborn."
'Katie Price: My Crazy Life' airs at 10pm on Monday exclusively on Quest Red and dplay.