Black Eyed Peas singer Fergie is riding high on the success of her first solo album, The Dutchess. But, as she admits in the new issue of Time, feeling high in the past meant using crystal meth.

"It was the hardest boyfriend I ever had to break up with," she says. "I dug deep as to why I got there. It's the drug that's addicting. But it's why you start doing it in the first place that's interesting. A lot of it was being a child actor; I learned to suppress feelings."

These days, performing is her outlet for those feelings. "We're on tour," she says. "I have an hour and a half of performing every night and improvising. If there's a rafter, I can climb right on."

And while her nickname comes from her family – "My grandpa's Fergie. My dad's Ferg. And I'm Junior," she says – she's familiar with that "other" Fergie, Britain's Duchess of York. "She called me on the phone," says the Southern California-born singer (real name: Stacy Ferguson). "We're talking about doing some charity work together, building schools."