Sharon Osbourne's heart "needs protecting".

Ozzy and Sharon Osbourne

Ozzy and Sharon Osbourne

The 64-year-old star made the admission as she posted a sweet throwback picture of her and her husband Ozzy on social media to mark their anniversary.

She wrote on Instagram: "Thank you Ozzy for 35 crazy & wonderful years. You carry my heart in yours, and it's getting older and needs protecting. Happy Anniversary (sic)"

It comes after Ozzy and Sharon renewed their wedding vows in an "intimate" ceremony.

A source said: "This is something Sharon has wanted for some time. She had been talking about the possibility with friends since last year after dealing with their problems.

"But when it came to the day itself she wanted to keep things very low-key. They are obviously used to doing everything in the spotlight but made a conscious decision to keep this quiet. It was just an intimate family get-together at the hotel with their children and very nearest and dearest there."

And Sharon recently admitted she had to fall back in love with her husband after he cheated on her.

She shared: "35 years with someone is a hell of a long time. And I think I fell out of love with my husband and then fell back again. I forgive. It's going take a long time to trust, but we've been together 36 years, 34 of marriage. I just can't think of my life without him.

"[I] probably, really, just months ago [fell back in love] because he was trying so hard to be a better person - desperately trying, working with his therapist every day and trying so hard. I just had a newfound love. And I respected him because he's seriously trying to be a better person."