Story highlights Heather Donahue memorably filmed herself crying in terror in "The Blair Witch Project"

She quit acting and followed her then boyfriend into a new life of growing marijuana

Donahue ended up living for a year in Nuggettown, California

In 1999, Heather Donahue was unexpectedly catapulted to stardom as a co-creator and costar of the indie horror film "The Blair Witch Project" -- who memorably filmed herself crying in terror in the genre-breaking flick.

A few short years later, just as unexpectedly, her acting career stalled. And soon she was embarking on the most peculiar of second acts -- that of marijuana grower.

"I took all my stuff into the desert related to my acting career and burned it all," Donahue, who turns 37 on Thursday, tells the Philadelphia Inquirer.

Well, she did spare one thing: the blue ski cap from the "Blair Witch" poster.

"That's the only thing I kept," she says. "I figured if things got really bad, I could always sell it on eBay."

At the time of "Blair Witch's" release, Donahue told PEOPLE that her newfound fame was " hilarious and overwhelming ." But soon she became disillusioned. "The acting projects I was lucky enough to work on weren't always things that I felt good about putting out into the world," she says now in a Q&A on her website. "I didn't see that getting better as I got older. I wanted to change my life, see what else was out there for me, what else I might become."

She ended up following her then new boyfriend into a strange new life of growing marijuana, mostly for medical purposes -- a journey she relates in her forthcoming memoir, "GrowGirl: How My Life After The Blair Witch Project Went to Pot."

Donahue ended up living for a year in Nuggettown, California, with a bunch of growers and their "pot wives," helping to build grow rooms and tending to the crops. She tells the Inquirer that she was "always an avid gardener" and quickly fell into a routine, becoming "a solitary country girl" after her years in the fast lane in L.A.

She gave up growing pot after deciding to write about it -- and after a friend got busted by the feds.

Donahue, who is now on a book tour, is torn about whether marijuana should be legalized. On the one hand, she's worried that corporations might run over the mom-and-pop growers. But at the same time, she thinks it's foolish to outlaw it.

"Cannabis has been intertwined with human culture for thousands of years," she says on her website. "It's here to stay as medicine, as an industry, and as a component of the culture. The idea that such a hearty, useful plant could be legislated out of existence seems pretty foolish, especially in retrospect."