Nikki Quinn was diagnosed with cancer at 13, had an allergic reaction to chemotherapy and died on the operating table when her organs shut down.
But she was revived and after three-and-a-half weeks in an induced coma, she woke to find she had Bell's Palsy, which had paralysed one side of her body.
But despite still living with chronic pain today, the Sydney student says the hardest part was watching her friends die.
At 25, Nikki suffers from side effects including bone deterioration, nerve damage, hypersensitivity, chronic fatigue, weak lungs and osteoporosis.
Her incredible will to survive shines through today, but for a long time, she was ravaged by post-traumatic stress disorder and survivor's guilt after her traumatic childhood experiences.
"My pain was at its worst and I was feeling sorry for myself," she told news.com.au. "Some days I can't get out of bed, I feel like I'm being crushed.
"I lost nine friends altogether in hospital. I saw them fight as hard as I did, I was as close to death as they were, I always wondered why I survived and they didn't. I miss them so much."
Nikki remained close with her friends' families, but secretly suspected they must hate her for living while their loved one didn't make it.
The softball-playing teenager had just started chemo for acute lymphoblastic leukaemia when her first friend died, a boy who had been having the same treatment as her.
"It was really scary. Keegan went into remission but it was the treatment that killed him in the end. It was the chemo, my mum explained, as best she could to a 13-year-old essentially having the same kind of treatment.
"It was confusing - it can take away your life as quickly as it helps you recover."
Then there was Montana, the three-year-old girl who would skip up and down the ward with her mother and come in to give Nikki a kiss. "I wished I could get up and walk with her. She kind of inspired me to push myself to walk again."
There was the friend with a rare form of cancer, the friend who loved cricket, the one who introduced her to alternative therapies and the boy who played for Parramatta Eels, who asked about her scars when he found out his cancer had come back.
Brett, with whom she went to camp, died at 18 after the two of them had spent years acting as role models for the younger kids.
"I felt I needed to be strong for them, so they weren't as afraid," she says. "One day, a girl called Shannon wouldn't take her nausea medicine, she just refused, so her mum asked, 'If Nikki gives it to you, will you have it?' She let me give it to her.
"No matter how old they were, they knew I was going through what they were, that I understood them on a different level."
The loss of those friends left a hole in Nikki's life that her schoolfriends couldn't fill. "It's hard for people to understand," she said. "Even if I look OK on the outside, I never go clubbing because even if I don't drink it would take me a week to recover."
Nikki now leans on brother Matt, mother Tanya, boyfriend Jade and a few close girlfriends. She hopes to work as a nurse at The Children's Hospital at Westmead, where she was treated, and helps families through the Children's Cancer Institute. It has helped her overcome her crippling guilt.
"It's kind of given me a purpose," she says. "It makes me so happy helping them. My pain seems so irrelevant.
"They can see their child can come out the other side.
"The only reason I feel like a burden is because I'm 25 and have to depend on my mum so much. I hold her back a bit and that hurts."
Nikki had to relearn how to walk, drink, eat and write. She suffers from pneumonia every winter, and has to see different specialists every couple of months to run tests for all her different problems.
For a while, she was on enough painkillers to knock out a grown man, but she stopped taking them because they were damaging her liver, and now simply lives with the pain.
Despite severe problems with her lungs, low bone density and nerve damage to her feet, she's been training with Jade in the Blue Mountains for a five-day trek in Peru to raise money for cancer research.
"My doctor kind of laughed at me, he didn't think I was serious. I think it's going to be tough," she said.
"I've watched some videos where people doing it look short of breath because of the altitude and that scared me a couple of times.
"I'm going to have my angels in the back of my mind.
"If I can get through what I have, this will be a walk in the park in comparison."