"I started dancing almost immediately after I learned how to walk," the actress – who's partnering with I Am a Dancer Against Cancer, a nonprofit created to provide financial support to dance educators, dancers and parents impacted by cancer – tells PEOPLE exclusively. "It will always be a part of who I am and how I express myself."
Nearly two years ago, the star and her boyfriend Austin Butler were dealt a devastating blow when the actor's mother was diagnosed with stage-three cancer.
"It was shocking," she says. "I had never dealt with cancer personally and to hear that word, it was just like a punch in the stomach."
A few months later, Butler's mom died from the disease. "You always think that you're going to make it through and you're going to overcome it, but sometimes that doesn't happen. Cancer is very aggressive and it doesn't take pity on anyone or anything."
Just one year later, Hudgens' own father was diagnosed with cancer as well. "It felt like it was some mean joke," she says of her dad's stage-four diagnosis. "You think you're going to make it through, you're there with them every step of the way, holding their hand, wanting it to be okay."
The night before the entertainer was scheduled to perform in the live TV production of Grease, Hudgens's dad lost his battle with cancer. "The thing that honestly got me through it was my community that I was surrounded by," she says.
"Every day I came to work, they all hugged me, checked in on me, made sure I was doing okay," she says of the weeks leading up to the production. "My dad passed away the night before my show, and it was shocking. I knew that it was coming, but nothing can prepare you for losing a parent."
But the star had her "second family," including co-star and fellow I am a Dancer Against Cancer supporter Julianne Hough, to "lift me up and let me know it was okay," she adds. "I dedicated my performance to my dad because I knew he was up there in heaven looking down on me as proud as can be."