01/12/2012 at 05:15 PM EST
With a year that included starring with Brad Pitt
in Tree of Life
, and earning a Golden Globe nod for The Help
, Jessica Chastain – who was a relative unknown this time last year – is having the time of her life.
"It's such an exciting [time]," the actress, 30, told PEOPLE at the Palm Springs International Film Festival. "I'm having an out-of-body experience right now. It's really shocking and lovely."
But as of a week ago, she still hadn't found the all-important gown for one of her biggest walks down the red carpet.
"I'm narrowing it down," she said of her dress selection for Sunday's Globes, adding, "It's very, very exciting. I don't know yet, but hopefully it will be beautiful."
But it seems the excitement for Chastain has only just begun. She has a handful of films in the works for 2012, including Tar
, co-starring James Franco
, Michelle Williams
and Mila Kunis