Green Day singer Billie Joe Armstrong talks in the new Rolling Stone about the drug use that landed him in rehab last year, revealing that he used to carry so many prescription pills around that his "backpack sounded like a giant baby rattle." He also admits to using "prayer through meditation" to help stay sober.

Armstrong was shipped off to rehab following an onstage meltdown at last September's iHeart Radio Festival in Las Vegas. The substances he was struggling with weren't identified at the time, but Armstrong told Rolling Stone that he was overindulging in alcohol and prescription drugs. "I started combining them to a point where I didn’t know what I was taking during the day and what I was taking at night," he said. "It was just this routine."

And his routine involved abuse before and after performing with Green Day -- a revelation that hardly comes as a surprise to anybody who caught the Vegas breakdown. "I played onstage loaded a lot," Armstrong said. "I’d have anywhere from two to six beers and a couple of shots before I went onstage, then go and play the gig and drink for the rest of the evening on the bus."

But that life is now a thing of the past, thanks in part to his embarrassment over the iHeartRadio incident.

"This was the last straw. I had no choices anymore," he said. "People will remind me a little bit. Or I’ll see a photograph. And it makes me so sick. No. I can’t go there. That’s my last drink. Which is good -- it’s documented. Anytime I feel like drinking, I can think about it."

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