04/30/2013 at 12:00 PM EDT
There was a time last year when Vanessa Hudgens
looked in the mirror and didn't see herself – she saw a homeless, abused girl.
Her hair cut well above her shoulders, she saw her character from her upcoming movie Gimme Shelter
. The problem was, her filming had been completed.
"I had a struggle, for sure, finding myself again," Hudgens tells PEOPLE. "But with diet and with working out and increasing that serotonin, I got back to who I am."
In the film, Hudgens plays Agnes Bailey, a teenager forced on the streets in an attempt to find her father. (See the shocking movie make-under here
Her hair now grown out, Hudgens donned an All Saints dress and Valentino shoes at the grand opening of Las Vegas's Hakkasan Nightclub on Saturday. While she looked stunning, she says it took a while to feel normal again, considering her previous mindset.
"It was my first departure that I did. I chopped all my hair off for it," she said. "I pushed myself so hard and so far and as soon as we were finished filming I had no clue who Vanessa was. I had to find myself again. It was an amazing journey and an actor's dream."