Princess Diana is typically remembered through rose-colored glasses: smiling, laughing, and constantly looking out for those around her. But according to a new documentary, the People’s Princess was dealing with mental-health struggles behind closed doors.

“The bulimia started the week after we got engaged,” she said. “My husband put his hand on my waistline and said something like, ‘Oh, a bit chubby here, aren’t we?'”

Diana: In Her Own Words—which aired on the National Geographic channel earlier this week—reveals a little-known side of the late princess, just months after her children (Prince Harry, Prince William, and his wife, Kate Middleton) participated in a video aimed to destigmatize mental-health issues. The documentary pulls from a series of interviews that Princess Diana’s friend James Colthurst conducted in 1991 at London’s Kensington Palace.

Diana was brutally honest about struggles in her marriage to Prince Charles, who was not only unfaithful to her before they even got married but who, through crude comments, may have set the stage for an eating disorder.

“The bulimia started the week after we got engaged,” she said. “My husband put his hand on my waistline and said something like, ‘Oh, a bit chubby here, aren’t we?’ And that triggered off something in me.”

Then just months after her 1981 wedding, matters only got worse as she started having suicidal thoughts, only to have experts try and “fix her” with medication.

“I was about to cut my wrists,” she said. “I came [back to London] to seek treatment. I was in such a bad way. Couldn’t sleep, didn’t eat, the whole world was collapsing around me. All the analysts and psychiatrists you can ever dream of came plodding in. Tried to sort me out. Put me on high doses of valium. It was me telling them what I needed. They were telling me, ‘Pills.’ But the Diana that was still very much there decided that it was just time, patience, and adapting that was all that was needed.”

Time was indeed a healer, and the princess gave major mental-health props to something you’d never expect: a haircut. The refreshed look she got in 1990 from celebrity hairstylist Sam McKnight made her feel like a new person.

“I suddenly felt so much stronger, mentally and physically, so I was able to soldier on.”

“I suddenly felt so much stronger, mentally and physically, so I was able to soldier on,” she said.

Soon Diana shifted the course of her life, making it less about her unhappy marriage and focusing more on positive endeavors: She devoted countless hours to charity work and worked to change the public’s mindset on everything from HIV and AIDS to leprosy. She also focused her attention on her sons, teaching them both a modern approach to monarchy that focused on the people, not the titles.

“It took me six years to get comfortable in this skin, and now I’m ready to go forward.”

Given what Princess Diana claimed to be her greatest achievement at the time of the interview, it’s safe to say she practiced what she preached: “To not bow down to pressure,” she said. “You know, not let all this chat disturb me. It took me six years to get comfortable in this skin, and now I’m ready to go forward.”

Diana’s struggles can teach us all an important lesson: No matter what you’re going through in life, there’s always a way to begin to turn things around. Even if that just means scheduling a trip to the salon.

According to the World Health Organization, depression is the globe’s leading health threat—and this workout can help fight the disease.