Taylor Momsen doesn't know how to relax

Taylor Momsen has certainly come a long way from her How the Grinch Stole Christmas days.

Gossip Cop reported the 18-year-old former Gossip Girl star is all grown up and has the work life of someone who just graduated college and is starting out in an entry-level job.

"I sleep for about four hours a night, or day, really. I go to bed at 9 a.m., sleep for four hours, then get up and start the day again,” she said in an interview with FHM UK’s February/March issue.

According to Us Weekly, Momsen has become so used to her grueling schedule, that she doesn’t know what to do with any downtime she gets.

“I'm completely neurotic, totally anxious and high-strung all the time," she said.

"To be honest, I don't know what to do when I'm not working. I lose my mind if I'm not constantly doing something."

The Pretty Reckless singer, who officially left the CW’s hit show along with co-star Jessica Szohr in May 2011, has since turned her focus away from acting to further her career as a musician.

During that transition, she’s also swapped her high-end Manhattan clothes for black, chains and studs.

"I love stripper shoes and I always try to find the tallest ones. I'm always surprised no one talks about my shoes. I'm, like, on stage in 15-inch heels but people talk more about my eye make-up, which has stayed the same forever," she said. "I always think that's funny."

Momsen added that she "got into heels when I was little, though. My mom's really short so she always wears really tall heels and I used to steal them and now it's just a part of my everyday life.”

Let’s hope she doesn’t break her legs with those 15-inch heels.