Her Saturday Night Live gig marked the first time the singer pulled double duty on the show.

Hosting NBC's Saturday Night Live can be nerve-wracking for anyone — even a Grammy-winning superstar like Billie Eilish.

"Preparing for SNL was f---ing nuts, dude. It was literally alien," Eilish revealed to Howard Stern while visiting his SiriusXM show and recounting her recent experience. "I cried every single day of the week. No joke at all."

This wasn't Eilish's first time stepping into Studio 8H, as the singer previously performed as the show's musical guest in 2019 for the season 45 premiere. But Saturday's episode was her first time pulling double duty, hosting in addition to performing songs from her new album Happier Than Ever.

And while singing is something Eilish knows like the back of her hand, acting wasn't exactly something she felt confident about.

Saturday Night Live
BIllie Eilish hosting "Saturday Night Live."
| Credit: Will Heath/NBC

"I was just scared," she said, recounting how she cried in the green room from the pressure she was putting on herself. "It's like, it's SNL… These amazingly talented actors are surrounding a table where, somehow, I'm the main course."

She went on to reveal that her reactions manifested in more than just intense nerves, telling Stern, "I threw up on a plane coming here. I had crazy s---s when I got here like you wouldn't believe… you know, ones where you have to get fully naked on the toilet."

Eilish admitted that a lot of her worries came from stepping into a world of seasoned professionals. Fortunately, SNL is known for taking care of even the most novice of performers, and Eilish says as soon as she stepped on the stage for the live dress rehearsal, everything got better.

Saturday Night Live
Billie Eilish and Kate McKinnon on 'Saturday Night Live.'
| Credit: Will Heath/NBC

"As soon as I saw the crowd and felt their joy, it was like I wasn't nervous. It was relieving," she said. "I was like, 'Oh, this is actually really incredible, and I don't have to worry. This is just for fun.'"

Performing her monologue as "Sexy Mrs. Claus?" Inviting Kate McKinnon over for Christmas dinner? Mugging with McKinnon and Aidy Bryant in a corporate hotel ad spoof?

Yeah, we'd say Eilish looked like she had fun. Watch Eilish's interview with Stern below.

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