Nick Cannon is revealing for the first time the severity of the health scare that forced him to step down from his daily radio show and the lifestyle changes he's been forced to make since being hospitalized twice this year for kidney-related problems.

"I scared a lot of people.  I scared myself," Cannon said today on " Good Morning America" in his first morning television interview since being hospitalized in Aspen, Colo., in January.

Cannon, 31, was hospitalized while on vacation with his wife, Mariah Carey, and their 10-month-old twins. He was transferred from Aspen to a Los Angeles-area hospital where he was diagnosed with kidney failure.

"The technical term is lupus nephritis," he said.  "It's a rare form of lupus that's just attacking my kidneys.   They thought it was just kidney disease and then they were trying to figure out why my immune system was attacking my kidneys and that was sort of the root of it all."

Just weeks later the "America's Got Talent" host found himself back in the hospital again when doctors discovered he had blood clots in his lungs and an enlarged heart.

"My kidneys were in tip-top shape but I started to feel pain again," Cannon said.  "And because of my schedule and everything I had a few blood clots in my lungs which then affected my heart as well.  A lot of people have passed away from that and the doctor said luckily I was in such great shape and taking care of myself because a lot of people have been taken down by it."

According to the National Institutes of Health, the disease Cannon was diagnosed with, lupus nephtritis, is an autoimmune disease that affects approximately three out of every 10,000 people.  Left untreated, it could worsen to kidney failure.

To avoid that fate, Cannon, he revealed, has been ordered by doctors to make dramatic lifestyle changes, both professional - he announced Feb. 17 that he would step down as host of his daily radio show - and personal.

"I have been ordered to sleep at least six hours a night," he said.  "They say rest is probably the best medicine.  I'm dealing with it. Of course I'm not used to the medicines, but I feel like I'm starting to figure out a lot of holistic ways, meditation and stuff to get through it."

To get through the other most dramatic lifestyle change, the diet, Cannon revealed he relies on his wife, whom he calls, "Dr. Carey."

"The diet is the worst part," he said.  "I can't have any fast food anymore…no Happy Meals, nothing."

"She made me an egg-white sandwich before I left the house this morning," he said of Carey.  "Those are the things I have to be eating now, no more bacon.  She takes care of me, makes sure I'm eating what I'm supposed to be."