Ten days before Christmas 2013, Hollie, then 15, was admitted to hospital after being diagnosed with anorexia nervosa, anxiety, and depression.
After suffering in silence with depression and anxiety for three years, she had stopped going to school and started restricting what she ate a few months earlier.
But Christmas was when it hit hardest: Being around so much food was so difficult that she felt like she couldn't even go around the supermarket without crying at the sight of it all. At family gatherings, she felt under pressure to eat.
"I think you feel worse at Christmas because there's so much pressure on you to be happy and normal, and you have to socialise a lot," Hollie told BuzzFeed News. "You don't want to put a downer on everything, so you just have to try really hard to, like, keep yourself up and try to seem like you're fine."
After eventually telling her mother how she felt, Hollie was referred to the Child and Adolescent Mental Health Service, diagnosed with anorexia, depression, and anxiety, and admitted to hospital.
Faced with a wait until the new year to get full treatment for her condition, Hollie said she felt incredibly alone in her diagnosis. "I didn't know anyone else with it, so I had nobody to talk to," she said.
In fact, she was far from alone.
More than 21,000 people with mental illnesses spent Christmas in hospital as a result of feeling increasingly unwell during the festive period last year, according to mental health charity Mind.
In a recent survey of 1,100 of the charity's supporters, they found that 36% of people polled had self-harmed to cope with the pressure of Christmas, while 52% had considered self-harming and 45% had considered killing themselves.
A further 76% of people reported having trouble sleeping and 60% of people have had a panic attack over Christmas.
During her time in hospital, Hollie visited Mind's website, where she came across others who had experienced what she was going through and found herself feeling much less alone.
As well as providing information and advice about mental health, Mind hosts Elefriends, a supportive online community where people who are struggling can share their experiences with others.
"Just to know that you weren't alone made a huge difference," Hollie said of the help and advice she found while she was at her most unwell. "You can see that recovery is possible."
Now that Hollie has made a full recovery from anorexia, and has her anxiety under control with medication, she has one message for others going through what she did: "Help is always out there and you don't have to suffer alone."
"This time last year was still pretty rocky, even though I was a lot better than the year before, but this Christmas will be the first time it's felt normal in about two years," she told us.
Hollie said that she finds it important to use social media, using the #MedicatedAndMighty hashtag, as well as updates on her recovery on Instagram, to raise awareness of what she went through, and she is determined to get involved with working in mental health in order to help others like her.
Having overcome her own struggle, Hollie said she will be spending this Christmas "chilling with my family. Nothing too hectic.
"Just keeping it calm."