"Post-cancer depression and anxiety is hard to talk about," says Ethan Zohn, who has been in remission for 7 years

Cancer survivor Ethan Zohn credits CBD, a non-intoxicating chemical in the cannabis plant, for giving him back his mental health.

“The constant fear and anxiety of my cancer coming back was debilitating,” says the Survivor winner, who was first diagnosed with Hodgkin’s lymphoma in 2009. “I suffered in silence — and it’s not a great way to live.”

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Zohn, who chronicled his moving battle with the disease on PEOPLE.com — including when he relapsed in 2011 — underwent a second stem-cell transplant in February 2012, and has since been in remission.

But, he tells PEOPLE, his health problems didn’t end when the cancer went away. “Once I was given that clean bill of health and sent back to my normal ‘everyday’ life, that’s where the anxiety and the fear kicked in of what had just happened to me,” he says, adding that his father passed away from cancer when he was 14. “So to me, cancer equals death,” he says. “The fear and the loneliness — and the fear of the cancer returning after I was in remission — was totally paralyzing.”

Image zoom Issac Solotaroff

Zohn, 45, is sharing his story as part of a new video series to spread awareness of CBD’s health benefits created by cannabisMD, a non-advocacy, consumer education platform, which is also behind a new billboard in Times Square that profiles Zohn.

“Part of the uncertainty and all of the invisible scars that need healing from cancer is the anxiety and fear of relapsing: What if the chemo didn’t work? What if I die? What if I get another form of cancer because I ate a bag of chips?” he says. “I was paralyzed and not living a life that was worth living because I would just sit around and ruminate about what I thought may happen. Anytime I had a simple little itch on my leg it was like, oh my god, the cancer’s back.”

Finally in 2012 he found relief in CBD — and occasionally cannabis.

“It calmed my mind and restructured my thought patterns and got me out of this vicious cycle of destructive thoughts,” says Zohn, who lives with wife Lisa Heywood in New Hampshire. “I was able to sleep better, I was able to interact with my friends and family in a better way, I wasn’t as anxious and jittery.”

These days he takes 25 mg of CBD in the morning in the form of a tincture, which he likens to a multivitamin. “CBD gives me a sense of calm and confidence that makes me feel a little better about myself and more confident in my body, and reminds me that my body in an incredible thing that can heal itself,” he says, adding that he hopes sharing his story will lessen the stigma of CBD and encourage other people living with anxiety to consider CBD treatment.

“I’m not a hippie who thinks modern medicine is a fraud — I truly believe in it, and I know the work doctors do is saving lives,” says Zohn. “They saved mine.” But he also sees the natural appeal in CBD. “To use a drug that is derived from nature to make myself feel better, to use something grown from the earth, that makes sense to me. I could take 10 pills to get to sleep at night, or else take some CBD or eat a pot brownie.”

Image zoom Issac Solotaroff

And while most experts agree that CBD may have some health benefits, the general consensus is that more research needs to be done. “It’s an extremely promising compound and there are a lot of studies that show its potential,” Dr. Kevin Hill, addiction psychiatrist and Director of the Division of Addiction Psychiatry at Beth Israel Deaconess Medical Center, previously told PEOPLE. “But while pre-clinical or animal studies show CBD may have anti-anxiety properties and may be antipsychotic, for the majority of uses, there is not a lot of evidence.”

But for Zohn, there is no doubt that using CBD and cannabis has improved the quality of his life.