The 47-year-old actor is featured in the August issue of GQ, where he opens up about his split from the actress. The two married in May 1998 but called it quits in 2003, ultimately finalizing their divorce in 2005. They share two kids together, Maya, 20, and Levon, 16.
Hawke says that going through divorce caused his personal life to crumble, and admits he was suffering from depression at the time.
"I got divorced and my personal life fell apart. I don't know if you feel this way, but when you're depressed, it's really easy to see everything that is fake about other people and life, and I just started seeing all that," he says. "How phony celebrity was, how phony everything is. You channel your inner Holden Caulfield, you know?"
When asked what brought him out of those dark times, he credited "work, theater, my kids."
"That's the wonderful thing about children is they just need you every day," says Hawke, who also shares two kids -- Clementine, 10, and Indiana, 7 -- with wife Ryan. "It gives your life balance. Meaning your whole life isn't just about yourself."
Later in the interview, Hawke also reveals that he has taken on acting roles over the past few years to pay for alimony, a court-ordered provision.
"I pay my alimony with my acting, I pay my kids' health insurance with my acting," he admits. "I pay everybody's tuition with my acting. I'm helping various charities with my acting. I've become a professional, and I never wanted to be a professional. I kind of hate professionals."
However, with the upcoming film, Blaze -- in theaters Aug. 17 -- Hawke says he was able to tap into his creativity as a director, accepting the rare opportunity to make a movie instead of money.
"My best movies are not the ones that pay me: the Before trilogy, Boyhood, First Reformed, Dead Poets Society," he explains. "When I get left alone in a room for a second and I get to be creative again, I'm like, 'OK, Ethan, you get to make a movie.'"
Though they've had their ups and downs over the years, Hawke and Thurman have remained amicable for their kids. Hear how Maya is following in her parents' acting footsteps in the video below.