Kelly Osbourne is mourning the loss of her father Ozzy following his death on Tuesday. Osbourne posted a brief message to her Instagram stories on Thursday afternoon. “I feel unhappy I am so sad,” she wrote. “I lost the best friend I ever had.”

The Fashion Police alum took to her Instagram Stories to share a sweet throwback moment from Ozzy & Jack's World Detour, the A&E reality series featuring Ozzy and her brother Jack Osbourne.

Osbourne, fondly nicknamed the “Prince of Darkness,” was married to his second wife, television personality and music manager Sharon, from 1982 until his death. Together, they shared three children: Aimee, 41; Kelly, 40; and Jack, 39.

Ozzy Osbourne welcomed two children with his ex-wife Thelma Riley and three children with Sharon Osbourne. He also adopted Thelma's son from a previous relationship. Here's everything to know about Ozzy Osbourne's kids.

They were just totally in love and devoted to each other, and that wasn’t for the cameras. That was just who they were.”

Tributes are pouring in from music legends and celebrities after Ozzy Osbourne, the rock and heavy metal icon turned reality show star, has died at the age of 76, according to his family.

The musician’s death came just 17 days after he performed his final concert with Black Sabbath at England’s Villa Park, a swan song he’d been planning for months. “That show meant everything,” the source says. “It brought his career full circle.”

The back catalogue of Ozzy Osbourne and his band Black Sabbath has surged in the charts following the rockstar’s death. Black Sabbath’s signature song Paranoid, a number four hit in 1970, has returned to the Top 40 (at number 32) for the first time in nearly 45 years,