After finally being reunited with Atomic Kitten, 12 years after they split, Kerry revealed how her divorce from Brian drove her to a breakdown and worsened her drug addiction.
She said: "He left me. He got with somebody else and that absolutely destroyed me it made me feel a failure as a woman, as a wife and as a mother."
Kerry previously spoke of her hurt following her initial split from Brian, revealing to The Sun: "I couldn't make love to Brian - I made him sleep on the floor.
"I couldn't let him touch me I had images in my mind of him and this woman. I wasn't eating properly, I couldn't sleep...
"I couldnt rip the pain and rage out. It ended in me having a breakdown. I blamed myself, I kept asking if it was because I'd had our baby, Molly, and put on weight."
Brian previously revealed the details of his stag do, which started with lap dances on a bus and ended in him asking Simon Cowell for help in covering up his cheating.
He told the paper: "I was sitting on the bed when the woman undid my flies and began to perform oral sex.
"I was disorientated, it was very unexotic and unerotic. It lasted all of 30 seconds before I realised how stupid I was being."
Kerry, 32, went on to admit how the pair tried to patch things up when the stripper sold her sex story on Brian after his infidelity.
But following her stint on I'm A Celebrity, Kerry fell apart, splitting from Brian officially and eventually marrying Mark Croft - which, in turn, led to her cocaine addiction.
She added: "Unfortunately, the two came hand-in-hand. Cocaine becomes your best friend in the world and it listens to your problems."
Kerry has now been clean for three years and credits fitness bootcamp for breaking her addiction.
She admitted: "[The bootcamp] came just at the right time. And it might sound silly, but exercise changed my life. I've now been clean for three years."
[ Related article: Kerry Katona and Liz McClarnon admit they fought over Brian McFadden ]
[ Related article: Kerry Katona is 'panicking' over her weight ahead of The Big Reunion show ]
Kerry Katona had a little emosh moment on The Big Reunion last night, opening up about the moment she found out that ex-husband Brian McFadden had cheated on her with a stripper - and how it eventually led to her drug addiction.
Top stories on Yahoo Celebrity
1 - 8 of 24
Today on Yahoo
1 - 8 of 48
Top videos on Yahoo Celebrity
1 - 4 of 5