By Elizabeth Leonard
November 18, 2013 12:00 PM

As a little girl, Mariel Hemingway always began the night full of hope. Maybe, she’d think with childlike optimism, this evening won’t end with tears, blood, spilled wine and shattered glass. Just maybe, things won’t escalate in alcohol-fueled rage and then recede into chilly quiet. “I’d think, ‘Oh, it’s going to be a happy night.’ I fell for it every flipping time,” says Mariel, now 51, of her parents’ nightly ritual. “Wine time,” as they called it, began pleasantly enough. At 5 p.m. her father, Jack Hemingway, cooked up, say, freshly caught trout at their house in Ketchum, Idaho, while her mother, Byra, looked on, drinking dry cabernet on ice. Then things would turn. “It would get tense, and it would get ugly, very loud, and all the walls would come down. Then everybody would get quiet, and we’d eat gourmet meals on TV trays and watch Jeopardy! in silence.”

From the age of 7, it was Mariel’s job to pick up the pieces. She padded downstairs late at night to collect wine bottles or mop the floor. Her sisters Margaux and Joan were 7 and 11 years older, but “I was the cleanup girl,” she recalls. Looking back, the granddaughter of writer Ernest Hemingway realizes she grew up in “a house of insanity.” Back then, “everybody was on edge and nobody spoke about anything.”

Such despair and denial set the tone for much of Mariel’s life. “Tragedy was in my wake,” says the actress and author, who for years was haunted by an infamous legacy marked by generations of addiction and mental illness. At least seven family members committed suicide, including her supermodel sister Margaux, and her famed grandfather Ernest, who shot himself in the head a few months before Mariel’s birth. While she’s happy and healthy today—devoted to her daughters Dree, 25, a model, and Langley, 24, an illustrator, and her boyfriend Bobby Williams, 50 – finding peace took decades. During a recent visit to her rustic ranch in the Santa Monica Mountains, she admits ruefully, “I was so afraid one day I would wake up and go crazy too.”

In the documentary Running from Crazy, now in theaters and airing on Oprah Winfrey‘s OWN network next year, Mariel explores the “Hemingway Curse” and her fear that it would somehow befall her. “For most of my life, I didn’t think happiness really existed,” she says, sipping green tea in her cozy kitchen. “Until recently, it was all about survival.”

A dutiful child who sought refuge in nature, Mariel watched her sisters grab the spotlight. Margaux was rebellious; Joan, known as Muffet, showed early signs of mental problems and used LSD. “By the time I was 13, I knew my sister had issues, but no one ever talked about it,” says Mariel. When Muffet was in psychiatric hospitals, “I thought she’d just gone off to school.” Muffet was later diagnosed with bipolar disorder and schizophrenia.

Raised on secrets, the Hemingway girls hid another dark truth, Mariel says: Their father was inappropriately “intimate” with Margaux and Muffet in their teens. She recalls lying still as her dad visited the room the three sisters shared. “I didn’t see anything specific, but something funky was going on: some kind of uncomfortable intimacy. I think dad was trying to find love.”

Deeply conflicted about sharing the revelation because she loved her father, a writer and conservationist who died in 2000, Mariel hopes it will help “inform why my sisters were the way they were. The hard part for me is my father was a wonderful human being,” she says. “I know it in my heart of hearts that he didn’t even remember [in the morning]. I think living under the shadow of Ernest Hemingway was daunting for him. I don’t condone anybody doing weird s–t, but alcoholism is a bad disease, and you do f’ed up things.”

While Mariel steered clear of alcohol and drugs, Margaux spiraled. “She was very glamorous, and things were seemingly going well for her, but she was always drinking,” says Mariel, who recalls her slurring as they filmed Lipstick, Mariel’s breakout role in 1976. Margaux went on to overdose at age 41 on the eve of the 35th anniversary of Ernest Hemingway’s suicide.

But Mariel was not without demons; depression lurked behind her cheery exterior. “Everyone was like, ‘Oh, you’re the grounded one,’ but it wasn’t like I felt sane,” she says. Even after her own career took off, “I became obsessed with my body and with what I ate because I felt I could control it.” She compulsively exercised and fixated on extreme food plans, eating only fruit for days or fasting until her thyroid shut down. “It wasn’t like I didn’t have happy moments – like the birth of my children – but my underlying through-line was, ‘I’ll just get through it,'” says Mariel, who split from documentary filmmaker Stephen Crisman in 2007. At one point she contemplated suicide.

Today she is a woman transformed. “Finally I quit thinking somebody else had an answer, and I started to trust myself and found balance,” she says. She also found love. Her beau of nearly five years, Williams, a stuntman turned wellness advocate, offered solace. “He gave me permission to be childlike and enabled me to play and laugh,” she says. Williams says, “She didn’t have a childhood. She didn’t have family, friends or community. Now she gets to go out and play, whether it’s rock climbing, throwing a Frisbee or silly stuff like goofing off at the movie theater.”

At their home the two have created a wellness oasis with organic vegetable gardens, egg-laying hens and an outdoor playground with a climbing wall, trampoline, rope ladder, pool and teepee. Through books and speaking engagements, they aim to turn their healthy-lifestyle philosophy into a business while educating the public about options for treating mental illness and creating a balanced life. “The solution varies for everyone, but no one is or should feel alone,” says Mariel, who is also getting back into acting and developing TV and film projects.

But most of all, they laugh. “We go to restaurants and throw sugar packets at each other,” she says. “People look at us like we’re crazy!” The good kind.