Jack Osbourne, son of heavy metal icon Ozzy Osbourne, has revealed that he has been diagnosed with multiple sclerosis. The devastating news comes only weeks after Jack and his fiancee, Lisa Stelly, welcomed a baby girl named Pearl into the world.

In an interview with People magazine, Jack described his initial reaction to the difficult news: "I was just angry and frustrated and kept thinking, 'Why now? I've got a family and that's what's supposed to be the most important thing."

Multiple sclerosis is an autoimmune disease that affects the communication between the brain and the spinal cord, and can be extremely debilitating depending on its severity. It can cause loss of muscle control and balance, among other symptoms.

In a separate interview with Hello! magazine, Jack added, "I got really sad for about two days, and after that I realized 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."

A devastated Ozzy Osbourne told Hello! that the news of Jack's condition has left him both angered and confused. "If it was me, you'd think: 'Ozzy had a reputation and it caught up with him', but Jack is such a good guy," said the Black Sabbath singer.

Jack's mother, Sharon Osbourne, revealed to Hello! that she was riddled with guilt upon learning of Jack's disease. "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."

The family hopes that Jack can battle multiple sclerosis with drug treatments and lifestyle changes. His fiancee Lisa explains, "Jack will have to change his life for the better – get healthier, not get stressed – so I feel like this could almost be a blessing in disguise."

Loudwire sends its best wishes to Jack Osbourne and the entire Osbourne family.