When Magic Johnson's iconic basketball career was interrupted by a stunning HIV diagnosis three decades ago, the newlywed NBA legend had no idea how much time he had to live or how the virus would affect his wife and their unborn child.

"You just sit there and say, what does this mean? Am I gonna die?'" he told "CBS Mornings" co-host Gayle King.

Johnson, who remains HIV-undetectable to this day, opened up about living with the virus and his career in an exclusive interview for "CBS Mornings" nearly 30 years after he publicly announced his HIV diagnosis.

Today, the Lakers star is a loving father and grandfather, a successful businessman, a philanthropist and the CEO of Magic Johnson Enterprises. He and Cookie have been together throughout this time, and neither she nor their son, Earvin Johnson III, have HIV.

At the time of his diagnosis, Johnson thought the virus was a death sentence.

"I had to really learn a lot about the disease, HIV as well as AIDS. I had to make sure that I was open-minded enough to ask a lot of questions, go get a lot of information from different people," he said.

Johnson first learned of his diagnosis after a routine physical ahead of the 1991-92 NBA season. He was called back home from a pre-season game in Utah, so that Lakers team physician Dr. Michael Mellman could deliver the news in person. When Johnson first heard the news, he was "devastated," he said.