Kelly Osbourne (center) and her DWTS partner Louis van Amstel, with Ellen DeGeneres
Michael Rozman/Warner Bros.
09/18/2009 AT 01:05 PM EDT
Years of seeing her father, rocker Ozzy Osbourne, battle drug and alcohol addiction made it all the more difficult for Kelly Osbourne to face up to her own demons.
"I was ashamed of myself," Osbourne, 24, says on The Ellen DeGeneres Show
in an interview set to air Monday, Sept. 21. "I didn't want to tell my parents" – especially mother Sharon, 56.
"My mom had been in a relationship with my father for years and years trying to get him sober," says Osbourne, who is competing on the new fall season of ABC's Dancing with the Stars
with partner Louis van Amstel. "I was completely ashamed that I would have to go to her and now tell her that her daughter has issues as well.
"I felt like I let her down – but what I didn't realize was that if I would have went to her a long time ago, she would have helped me no matter what."
Osbourne describes how her first experiences with drugs at just 13 years old led to a pattern of abuse, which continued as the family's MTV reality show The Osbournes
Seeing photos in the tabloids of "the fat daughter of Ozzy Osbourne," she says, only made things worse.
"It was a lot for me to handle," she admits, "and I didn't handle it very well."