The news comes just two months after the 26-year-old TV presenter and moviemaker became a dad with fiancee Lisa Stelly.
MS is a disease of the nervous system which generates physical and mental symptoms including memory loss, slurred speech and dizziness. Its causes are not clearly understood.
Jack was diagnosed after he suffered the loss of 60% vision in his right eye.
He tells Hello: “While I was waiting for the results I got really angry. Then I got really sad. After that I realised being angry and upset is only going to make it worse.
“The timing was so bad. I’d just had a baby; work was going great. I thought, ‘Why now?’”
He says Stelly is responsible for keeping him strong as he comes to terms with MS, which affects each suffered in different ways.
His Black Sabbath singer dad is also finding the situation a challenge. He says: “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 wife Sharon adds: “I keep thinking, ‘What did I do wrong? What did I eat or drink when I was pregnant?’ I feel like it’s somehow my fault.”
Treatment includes drugs, physical and holistic therapy and lifestyle changes.
Last year Jack’s documentary about his dad, God Bless Ozzy Osbourne, was released on DVD. It’s to be broadcast on July 13 on US TV network Showtime.
-Classic Rock Magazine