The actress, who recently announced her split from her husband of nearly four years, Will Kopelman, tells Good Housekeeping in its May 2016 issue that her daughters, Olive, 3, and Frankie, 2, make her who she is.
"I thought I knew what love was, but holy cow, I did not," she says of her children. "I could never have imagined the kind of love I have for my children. I am who I am because of my daughters. I'm an overachiever parent, and not because I think I'm going to repeat the patterns of my parents."
Brian Bowen Smith
Barrymore's own upbringing was less than traditional, a childhood she doesn't fear her children will share. "I've already broken that pattern in my life," she explains. "But having grown up in the opposite way, I'm raising my children with all consistency, all protection. This is my chance to get it right."
The actress' protective nature toward her daughters isn't surprising – she and Kopelman noted in an exclusive statement to PEOPLE that their "first priority" is their children, and that they plan to remain a family.
But how is Barrymore working on her own well-being? A source previously told PEOPLE that Barrymore, 41, is remaining "optimistic for the future," and believes in love and happiness – sentiments she echoed in the Good Housekeeping interview, which was done prior to the announcement of her breakup.
Brian Bowen Smith
"Happiness is not this yellow, blithe, floating thing," she shares. "It's something that takes a tremendous amount of work. There's a warrior aspect to being happy. You've got to fight for it. And only when you've got that kind of earned happiness is it really good."
Barrymore has established a support system to help her achieve that happiness: namely, BFF Cameron Diaz, who previously said she "of course" reached out to the actress after hearing the divorce news.
"If you are in scary prison in the middle of nowhere, call Cameron," Barrymore tells Good Houskeeping. "She'll get you out. If you're looking for the best dinner-cooking partner and watching- TV-on-the-couch friend, call her. If someone is in a medical situation, call her! She's the most loyal, fierce, fun, cozy friend. We have incredible honesty with each other, and we work hard on our lives and our friendship. My girlfriends are my first family, and they know that I would lie down and die for them. My love for them is unbreakable."
Drew Barrymore Shares Her Favorite Childhood Memories
Don't expect Olive and Frankie to follow in Diaz and Barrymore's footsteps, beyond those attributes, though: "I'd never let them become child actors," she says.
"They'll have a chastity belt, a tracker system, no cell phones and we'll live in the middle of nowhere," she jokes to the magazine. "In reality, I'll just lead by example by being spirited, classy, consistent, philanthropic, hardworking, loyal to my friends and there any second they might need me."
Good Housekeeping's May 2016 issue hits newsstands on April 19.