Emma Willis feared Matt Willis would "never come home" after wild nights out.
The television presenter admitted she was desperate to help her husband with his alcohol and drug addiction and fully "believed he would".
She said: "I wasn't going to leave him because he had a problem. I wanted to help him, but he had to help himself and I believed he would."
And Emma admits it was their daughter Isabelle that changed things for Matt.
She added: "What really changed him was our daughter, Isabelle. Isabelle was his real ... Oh God, I'm going to start crying. Isabelle was his real focus. He was already doing it [recovery] himself, then she arrived and that made him even more determined."
Matt was 17 when he found fame in Busted and she admits there was a "real issue".
Asked what advice she would give to someone else in her position, she told The Telegraph newspaper: "I wish I knew, I'd make a bloody fortune. I'm not an addict, so it's a really hard thing to understand. Matt probably first went to rehab [in 2005] to get us all off his back. Then your relationship progresses and you realise that there is a real issue, and it's not just a young kid who has got a lot of money very quickly. But until he realised it had to change, there's nothing I could have done. Nothing."
And Matt previously revealed he and Emma have to "block out time" to see one another.
The Busted rocker said: "There were moments in our life where we were like, 'F**k man we never see each other.' We said, 'We can't do this anymore', Busted were on tour for about five months and she was working all the time so I would see her for like an hour or something like every three weeks. She'd have to work [when] I'd be home so it was becoming progressively more difficult, so now we block out time. We always have a month in the summer when we're together, and something has to be really f***ing important to break that up."