On the crowded beach, I was surrounded by lithe limbs and toned tummies.
Looking down at my own body, I felt sick. I was 14 years old and weighed a healthy 55kg.
I was fit too – an elite swimmer and a surf life-saving volunteer – but I still hated what I saw in the mirror.
When winter came, and I was swimming less, I worried about gaining weight, so became determined to slim down instead.
"I'm cutting out junk food," I told my mum, refusing her offer of a cheeseburger and chips for dinner.
I stopped eating ice-cream, too, even though it was my favourite.
Slowly, the weight dropped off. The more I lost, the more enthusiastic I became, so I started to reduce my portion sizes as well. Then I introduced rules, like not eating after 6 pm and not eating breakfast.
Soon, I was down to 48kg.
"I don't think you're eating enough, sweetheart," my dad said one night at dinner as I pushed steak and veggies around my plate.
I got even thinner, and my relationship with food became even more warped. I would only eat with chopsticks because I was scared there might be leftover calories on the knives and forks in the drawers, and whenever I walked past a Maccas, I'd hold my breath, scared I might inhale all the fat.
Soon, I was existing on just an apple and a single wheat biscuit a day.
When my weight dropped to 45kg, I collapsed at home, and my dad rushed me to the emergency room.
"Your heart and liver are shutting down," the doctor told me. "Without treatment, you'll be dead in 48 hours."
By then I was so numb, I didn't even care. I had to be fed by a tube for two weeks before I was allowed to go home. Mum and Dad watched me like a hawk for the first few days, so I ate normally.
But as soon as I could, I started cutting down again. My weight fell to under 40kg. My ribs were clearly visible, and my hip bones jutted out through my skin.
I got out of breath just walking a few paces. My energy was so low that I could only manage a half day at school, then I'd come home and sleep.
"Gemma, please let us help you," Dad begged.
But I wasn't interested. I shut down completely, going days without eating or speaking. It was like my emotions had been stunted; when my kitten Poppy got run over by a car, I didn't shed a single tear.
I started self-harming too, burning my arms with a hair straightener. When the burns blistered, I'd tear them off and rub raw chicken in the open wounds, hoping to catch some infection that would kill me.
I just wanted to die.
Eventually, I was admitted to an eating disorders clinic in Brisbane.
I was hooked up to a feeding tube, but when the nurses weren't looking, I'd puncture holes in it. Whenever I had to be weighed, I'd hide objects in my clothes, so I appeared to be getting heavier.
After eight weeks in the clinic, I'd been so devious; I'd hardly gained any weight.
Even then, I was furious with them for undoing so much of my hard work. I starved myself again, reaching my lowest ever weight.
I was still extremely depressed and terrified of food, but I started to experiment with ways of getting better. I made a list of all my old favourite foods – nuts, Freddo Frogs, hot chips, popcorn – and challenged myself to eat one each fortnight.
The first time I had a bite of chocolate in six years, I sunk to the floor shaking and crying. The feeling was a mixture of pleasure and pain.
After that, it was like the floodgates opened.
The next day, I ate a scoop of ice-cream, some chips, and a chocolate bar. The week after that, more ice-cream, three bags of chips, two chocolate bars, a bowl of cereal. The following week, a pizza, four burgers, and four Magnum ice-creams.
I was eating again, but this wasn't healthy. Each time, my binges got bigger. Afterwards, I'd either make myself vomit in the shower, or I'd collapse on the floor with severe stomach pains.
My weight shot up rapidly.
I went from my lowest weight to 40kg in a matter of weeks. Then I was 50kg, then 60kg. After seven months of binging six days a week, I hit 69kg. Suddenly, for the first time, I had a soft belly and legs that rubbed together when I walked.
My parents were thrilled, and everyone said I was looking well. But none of it made any difference – I was still utterly disgusted with myself.
I knew it was going to be tough, but I wanted so badly to get better for my partner who I'd met during my struggle.
I started to exercise and slowly reduced the number of times I was binging each week, and in time, I regained control of my eating.
It wasn't easy, and I had many relapses into either binging, starving or hurting myself.
Slowly, though, it got easier.
Now, I'm a healthy 56kg.
But I'm determined to tell other people suffering with eating disorders that recovery is possible.
If you or a loved one suffers from an eating disorder, there is help out there.
– The National Eating Disorder Collaboration has lots of information on eating disorders. They also have a list of state-by-state treatment services available.
– Lifeline (13 11 14)