Drew Barrymore is “freaking out” about growing old as she prepares to debut her HBO Original Movie Grey Gardens, co-starring Jessica Lange, later this month.

The beloved star, who celebrated her 34th birthday in February, says playing Little Edie Bouvier Beale, Jackie O’s reclusive first cousin, who goes from socialite to living with her mother in a deteriorating house, made her take inventory of her own life.

“I’m freaked out about how fast time is going,” Drew says in the May 2009 issue of Elle Magazine. “Now I get why adults are always so encouraging to young people – like, ‘Enjoy it! It’s magic!’ I’m in my thirties now, and I really want to try all the things that I haven’t gotten to do yet, like directing, and doing a drama. I’ve produced and gotten to do a lot of optimistic love stories, and that was so where I was at for 10 years in my life. And now I feel like, Okay, now I know how to do that. I wanted to get scared again.”

On preparing for the role of Grey Gardens’ Little Edie: “I did what I do when I have a big challenge lying in my path. I go to school. I shut the windows, the shades come down, the phone gets turned off, I don’t go out – I study.”

On completely transforming for the role: “I knew this was not a courtesy meeting, but not far from it. I didn’t want to come in there like a hungry freak. But I also felt every second counting. So – polite conversation, then he started looking through my binder, and I saw his demeanor change, actually noticing all the hard work I had put into it. So I just put it out there. I said, ‘Look – I have all of this inside of me, and I promise you that I will change my face to be her. I will learn how to stop talking out of the side of my mouth. I will go to school to relearn body language. I will shut out the world. I will not talk to my friends. I will give up my life for this, because I don’t think you can play this character and have a social life and balance the two mentalities. I won’t act. I’ll become this person.’”