I recently spent 15 minutes in a hospital waiting room thinking I was about to die.

Two days earlier I’d been in the ocean. I was surfing at my favourite break when, suddenly, my vision split in two, dissecting the golden sandstone cliffs reflected in the water all around me.

I paddled in, but it wasn’t until I was out of the water that I knew something was truly wrong. I was shaking, my head felt as though it was being cleaved open and a strange whooshing sound had begun in my right ear.

I called my partner, numb fingers fumbling with the phone, and he brought me home. I thought I might be having a migraine, something I knew women in their 30s could develop, so I tried to sleep it off, but the next day the symptoms persisted.

At the hospital, the MRI clunked and whirled around me. When the imaging was over the technician had a strange look on his face, as if I’d just performed a disturbing magic trick, and he sent me back upstairs to the referring specialist.

So, I thought, this is how it happens.

“You’ve had a carotid artery dissection,” the specialist said in a tone you don’t want to hear in a hospital setting.

The carotid arteries run up either side on your neck and supply oxygenated blood to the brain, he explained. One of mine had torn. It happens to about 2.5 per 100,000 people each year and there often isn’t a clear cause. The tear had created a bulge in the artery wall and the bulge had temporarily stopped blood flow to my brain. This is what had happened in the water, a transient ischaemic attack. Essentially, a mini stroke. The whooshing sound I could hear was my heart trying to push enough blood through the still-restricted artery. At any moment I could have a fatal or debilitating stroke.

I sat in the waiting room while the specialist spoke to a neurologist at Royal Melbourne about a transfer and potential emergency surgery. My existence seemed to contract down to each passing second.

When I was young, a friend died suddenly. It was late summer in Sydney and we were on uni break, jacarandas bursting like fireworks. He slipped near the pool at his house and hit his head, hard. He never regained consciousness.

Until then, I’d thought death was reserved for pets and grandparents. It came when and to whom it was supposed to. But in an instant this order had turned to chaos. Now I knew the truth: that almost every moment is an opportunity for unexpected and sudden death.

Alongside the grief, a subtle existential undercurrent now ran through my days. Because when you realise that the end to all this could be looming behind tomorrow’s sunrise, you start to feel pretty small in the grand scheme of things. I wondered how I was supposed to navigate life with my own mortality so close up. How are you supposed to live, to find meaning, when you know you can die at any moment?

As I sat in the hospital, waiting for a tiny bomb to go off inside me, the question that had formed 15 years ago swirled in my mind. Except now, I realised, I had an answer.

In a coincidence that made the walls of reality seem at their thinnest, I’d just signed a contract for my second young adult novel, The Edge of Everything, about a teenage girl trying to make sense of the sudden death of her brother.

Sitting in that waiting room I felt the truth of what I’d worked out when writing my novel finally sink into my bones, into my body: I’m alive. Right now, in this moment, I’m still alive, which gives me the opportunity to choose what matters, to create my own personal meaning – and just the chance to do that, even if it’s only for one more minute, feels like the point. It feels like enough.

The specialist called me back into his office. All the fear had fled his face. The neurologist had studied the scans. The danger, he said, had passed. With three months of aspirin and some rest, I was going to be OK.

Heading home I drove through my favourite type of light, the kind that shines marmalade and gold beneath billowy, deep grey clouds. It was beautiful, and I realised there is a very fine line between gratitude and fear. If you are too aware of the blessings of life, it can become a curse. There is such a thing as life being too precious. There is a middle ground needed to function in a non-neurotic way while still having awe and reverence for the fact that you’re alive, right now.

That day, I think I finally found it.

• The Edge of Everything is out now from Text Publishing (A$22.99)