The 'Osbournes' star also began to abuse drugs after learning of his mother's diagnosis, as he developed debilitating depression that left him wanting to take his own life out of fear of losing a loved one.
He said: ''It was just miserable and dark and weird and lonely. My mom was really sick, she had cancer at the time. It wasn't easy for her or the family because we were like, 'Oh, no. We are going to lose our mother.' So I just felt very, very alone. I started having kind of suicidal thoughts, and for me the best option amongst it all was just to kill myself.''
At his lowest point, the 33-year-old television personality disappeared for four days with the intention of overdosing, before his mother staged an intervention with the help of Jack's friend, who had told her the depth of his addiction.
When he returned home, his father and Black Sabbath rocker Ozzy Osbourne - who has also famously battled alcohol addiction - suggested they both enter rehab, and Jack checked in to Malibu's Visions Adolescent Treatment Center.
Now, the 'Ozzy and Jack's World Detour' star has been sober for almost two decades, and can't believe how low he once sank.
Speaking to the 'Dopey' podcast, he said: ''If there's ever a sign of the insanity of this disease, that's it. It's like 'Oh, you're miserable, just kill yourself.' ''
Jack's confession comes after 67-year-old Sharon - who is no longer facing cancer - revealed earlier this year that she too had attempted to take her own life three years ago.
Sharon admitted the decision left her brood - including Jack, as well as 36-year-old Aimee and 34-year-old Kelly - very angry, heartbroken and ''frightened'', and said their reaction has convinced her never to try again.
She said: ''Three years ago, I had a very bad time in my life and I just thought I'm going to bail, I can't take it anymore. I just can't take the pressure. It's not just me, many people feel this way. My husband found me and took me to the hospital ...
''Yes they [the kids] were terribly cross and heartbroken and frightened and everything that goes with it. When I was in treatment, there was two girls whose mother had committed suicide - two separate girls - and the damage that was left for them. I would never do it again.''
This article is dedicated to Caroline Flack.
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