John Travolta is opening up about the most painful time in his life, losing his son Jett who was just 16 when he passed away after suffering a seizure in 2009.

Speaking with Us Weekly, the 64-year-old actor looks back at this dark time.

Jett’s death, says Travolta, was “the worst thing that’s ever happened in my life. I didn’t know if i was going to make it.”

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He credits the Church of Scientology for helping him and wife Kelly Preston, 56, through this unimaginably difficult period.

“The church never left our side for two years,” Travolta adds. “I don’t know if I would have made it through without their support. Our church is the number one thing that keeps us grounded.”

Nearly a decade later, he says the loss of their son has led the couple to never lose sight of the importance of family.

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“Our children keep our interest in life very high. Their future is very important to us,” he reveals of their daughter Ella, 18, and son Benjamin, 8.

“They’re smart kids and they do well because they’re encouraged to apply what they learn,” he continues. “Ella is making a living as an actress. We’re very proud of her. She’s old-school elegant and gifted in the arts.”

Married in 1991, the couple also divulges the secret to their successful marriage. “We picked the right people and [keep] it honest and [communicate] and [check] in with each other,” says Preston. “A relationship doesn’t just happen. You have to work at it. You’ve got to keep it fun, and that’s what we do.”