In that three-year hiatus, in which there were rumors of drug addiction and even major weight gain circulated, something else definitely happened to Eminem that we didn't know until now -- he almost died.

The superstar rapper tells Vibe magazine in its upcoming issue that during a relapse, he overdosed on pills and almost became the focus of yet another hip-hop "RIP" song.

Em explained what happened in the mag's upcoming "Real Rap" issue, revealing that he almost kicked the bucket after his first stint in rehab.

"My doctor told me those mysterious new pills were methadone, which is used to wean heroin addicts off dope," Em said.

"Had I known it was methadone, I probably wouldn't have taken it. But as bad as I was back then, I can't even say 100% for sure. My doctor told me the amount of methadone I'd taken was equivalent to shooting up four bags of heroin. Even when they told me I almost died, it didn't click."

After detoxing, Eminem suffered a knee injury that required surgery, but because of his recent drug abuse, he was not prescribed painkillers. There was a point where he searched his home, top to bottom, in search of pills, and it wasn't until that moment that he realized he was an addict.

"I started looking around my house to see if I had a stash box of Vicodin ... I'm ransacking my house, finally find something in the basement, in a little napkin, seven and a half Vicodin -- the big extra strength ones -- and a few Valium," Em recalled.

"It never once hit me that drug addiction runs in my family. Now that I understand that I'm an addict, I definitely have compassion for my mother. I get it."

Today, Eminem has a year of sobriety under his belt, and has a new appreciation for his craft. According to the rapper, he's more productive than ever.

"I wanted to make an overall statement -- I'm back," the rapper said, regarding his forthcoming Relapse album. "It was a slow process. You gotta remember I hadn't recorded a song sober in seven years. So it took me awhile to even feel like I could record a song sober ... I don't know the last time I shot a video sober, without drinking or taking anything. It's been years."

"I almost feel like a little kid again with rap. I wanna play around with different flows. If I don't feel like it's what I'm fully capable of, if there's one weak line, I wanna change it," Em continued. "Rap was my drug. It used to get me high and then it stopped getting me high. Then I had to resort to other things to make me feel that ... now rap's getting me high again."

The full Vibe cover story with Eminem hits newsstands May 19th, the same day Relapse hits stores.