"They tell me that wherever they go, they have pain. They can never forget what happened," said Nagham Hasan, a 41-year-old gynaecologist from the Yazidi town of Bashiqa in northern Iraq.

"These negative feelings get transferred to me, too," she said.

When IS first rampaged across northern Iraq in 2014, Hasan fled with her family to the sprawling city of Dohuk further north.

Just a few months later, the jihadists descended on Sinjar, the remote Yazidi heartland in northwestern Iraq.

Declaring the secretive minority an "apostate" sect, IS killed Yazidi men, took boys as child soldiers, and forced thousands of women and girls into "sex slavery".

Those that could flee settled in camps and other shelters in Dohuk's hilly outskirts.

That's when Hasan's phone began to ring, and it has hardly stopped since.

Yazidi survivors asked about their sisters, wives, and daughters, who were not only physically wounded but also suffering panic attacks, insomnia, non-stop crying, and even suicide attempts.

Hasan began visiting survivors for medical consultations, which quickly expanded into impromptu therapy sessions as they detailed their traumatic experiences to her.

"The fact that I'm from the same sect played a huge role. It allowed them to feel closer to me, to trust me, to break that wall of fear," she told AFP.

- 'Dedicated my life' -

In recent weeks, dozens of Yazidi women and children have escaped IS's last desert holdout in east Syria, many of them making their way across the border to Sinjar.

But Hasan said there is a long way to go to heal the community-wide trauma, which has taken a vicarious toll on her.

"Seeing so many affected my own mental state. I'm a human being with feelings, too," she said quietly.

Her somber eyes are cupped by dark semi-circles, hinting at a lack of sleep.

She gets phone calls from survivors in the middle of the night. Some come visit her in the modest apartment where she lives with her parents, brother, and sister.

Her family tried to return to Bashiqa, retaken from IS in 2016, but found their home half-destroyed.

"My family life, my social life, my work were all affected by this work," said Hasan, tucking her thinning shoulder-length hair behind her ear.

She is dressed in a dark green sweater, matching blazer, and faded pink lipstick.

"I never married and don't have kids. My sister is studying medicine too, but I told her not to do the same thing I'm doing."

She began spending so much time on psychotherapy sessions and advocacy that she closed her women's health centre.

"I have dedicated my life to this now," she said, estimating that she has helped more than 1,000 Yazidis since 2014.

Each case is more heartbreaking than the last. One girl was raped 22 times by IS fighters. Another was eight when she was taken and assaulted.

Among her former patients is Nadia Murad, a Yazidi who escaped IS and won the Nobel Peace Prize for her activism on behalf of the minority.

Hasan keeps Murad's autobiography at home, the first page signed by the author.

"Each one of us fought Daesh with whatever we had, but you fought them with the strongest weapon when you decided to treat us," wrote the Nobel laureate, referring to IS by its Arabic acronym.

- Another shock -

Hasan said more than half her patients have resettled abroad, but those still in Iraq almost all live in camps with poor conditions and no breadwinner, which is slowing their mental recovery.

"Even after a survivor is freed from Daesh, she's hit with another shock when she comes to live in a miserable camp," she said.

As she walked down a dirt thoroughfare between shabby tents in the Kabarto Camp, Hasan was hailed down by a smiling woman.

Layla's 15-year-old daughter was abducted by IS at age 12, but was freed with her mother and treated by Hasan in the camp.

"She was inconsolable when she first arrived. She wouldn't talk, just cry. She's finally agreed to go to school, thanks to your help," she told Hasan.

A displaced man called out to Hasan, asking her to look at his infant's deformed arm.

After patiently listening, she promised to return for a proper examination.

Hasan is recognised by children, who wrap their thin arms around her legs, and even camp authorities say a warm hello.

She emerges from the camp visibly worn down, but determined: "I didn't think it would last this long, or that I would be doing this for years.