He also called the caregivers and family members of people living with MS "the heroes to me, in this battle."
When Osbourne was diagnosed with the incurable autoimmune disease in 2012, he was 26-years-old and a new dad.
"I thought my whole life was in front of me -- but there I was, being told I had an incurable and often debilitating illness," the former "Dancing With the Stars" contestant wrote. "I had so many emotions and so many questions, and, frankly, I was terrified of the unknown."
Now the father of two girls with wife Lisa Stelly, Osbourne credits his family with helping him through.
"My family was an incredible support system for me, helping me understand and wrap my head around the disease, and to them I am forever grateful."
As for his life now, Osbourne is committed to paying it forward with his work on the "You Don’t Know Jack About MS" awareness campaign with pharmaceutical company Teva Neuroscience, for which he is a spokesperson. He said he is hoping to educate more people about the disease and hopefully remove more of the stigma around it.
"I will never say that I am thankful for MS," he wrote in conclusion, "but I will say that without MS, I don't know if I would have made the necessary changes in my life that have changed me for the better."