Published Monday, 18 June 2012
The new dad has opened up about the autoimmune disease nearly two months after welcoming his first child with fiancee Lisa Stelly, revealing he found out he was suffering from the condition last month after he lost 60 per cent vision in his right eye.
He was treated in the same hospital that daughter Pearl Clementine was born in April.
In an emotional interview with Hello! magazine, he says: "The timing was so bad. I'd just had a baby, work was going great - I kept thinking, 'Why now?' ...
"While I was waiting for the final results, I got really, really angry. Then I got really sad for about two days, and after that I realised being angry and upset is not going to do anything at this point - if anything it's only going to make it worse. Adapt and overcome is my new motto.
Jack's diagnosis has left his famous family stunned; rocker father Ozzy adds: "If it was me, you'd think: 'Ozzy had a reputation and it caught up with him', but Jack is such a good guy."
And sister Kelly took to Twitter on Sunday to offer her thoughts, and asked fans to "support my brother in not only his bravery but honesty!"
She added: "I love you so much jack & I'm so proud of you!"
Jack's fiancee is determined he will pull through, revealing to Hello: "Jack will have to change his life for the better - get healthier, not get stressed."
Multiple sclerosis is an autoimmune disease that affects the brain and central nervous system. It can result in blindness and muscular weakness.