Kelly Osbourne believes becoming a mother saved her life because she was previously convinced she wouldn't live to see 40.

The TV star - daughter of Black Sabbath rocker Ozzy Osbourne - reached the milestone age on October 27 and she has now admitted she thought her battle with addiction would cut her life short but welcoming son Sid with Slipknot's Sid Wilson put her firmly on the right track.

Kelly - who is now sober - told Us Weekly: “I truly believe my baby saved me and made me a whole human ... You realise in that one second, 'You’ve given me purpose like nothing has ever given me before'.

" I don’t think I had purpose. I went from thing to thing to thing, and this level of self-hate and self-doubt that I used to have would just take me out."

'The Osbournes' star added: "I don’t believe God would’ve given me a baby during a time when I wasn’t mentally or physically prepared for it. [When] I was still actively drinking, still actively using … I would’ve been a terrible mother. I wasn’t selfless enough. I’m so glad it happened when I was a little older and I had my s*** together."

Kelly went on to reveal she still struggles with her sobriety when she has a bad day, but she is finding different ways to cope when she's feeling down.

She explained: "It’s a rocky road for me. Most days are great, but every now and then, I’ll get one really bad day where it’s hard to pull myself out.

"My natural habitual instinct is to numb myself because then I don’t have to feel the pain and I don’t have to feel unworthy. I can just hibernate.

"But you can’t do that when you have a baby. You absolutely cannot. Finding other ways of getting through those hard days can be difficult sometimes."