I was lying in bed in the early hours of a Sunday morning and wondering where my husband was, again. This wasn't the first time he hadn't come home for the night.

He'd confided that he was depressed. He had said he could feel himself spiralling out of control and was finding solace in long nights out with friends, then passing out on their couches. Often he wouldn't answer my calls and I'd have no word from him again until the next morning, sometimes afternoon.

I tried to be understanding. We'd moved from Sydney to New York and he had the pressures of a new job combined with the kick-in-the-gut that this city can sometimes become. He was homesick and I could sense it was hard on him. Yet something didn't quite click.

I left New York for a week with my mum and sister in Bali. It was just what I needed: sun, family, joy, a separation.

But when I returned home, our apartment felt different, ever so slightly off-kilter. I walked around carefully. My shoes weren't exactly how I'd left them, my jewellery box was in a new corner and my sweaters subtly rearranged.

I asked him if he had moved my things but he blew it off, never giving me a straight answer. As had become the norm, we argued.

The following morning, I went to make myself a cup of tea and found a Polaroid picture of the two of us, bizarrely stuffed at the back of the cupboard. I distinctly remembered that picture being on the fridge before I'd left. I walked to the fridge and immediately noticed that another photo was missing. I felt awash with dread but the penny hadn't dropped yet.

I inspected every photo of me in the house; they'd all been moved. As if from my subconscious, the words left my mouth: "You had another woman here."

He stared at me. He didn't hesitate. He held onto my shoulders, embraced me and looked into my eyes. "I promise you I had nobody here. Stop this. I've never been with anyone else."

I believed him, and yet I knew.

A few days later we were having dinner with friends when his phone started to ring. He looked blankly at the screen and then let it ring out. "It's work calling me." My chest tightened.

Then he got up and announced, "I'll call them back." He was tipsy and this was just getting sloppy. Why let a phone call ring out only to call them back 15 seconds later? He made the call, to his work, and everybody in the room heard the woman on the other end of the line say, "We didn't register a call to this number, sir." I turned to my friend and mouthed, "He's full of shit."

He saw me. "Are you f...ing kidding me?" he asked.

I stared back defiantly. "We all heard the receptionist say they never called you."

"This is a joke," he declared and stormed out of the room.

I felt embarrassed and confused.

The following day, he left without saying a word and still hadn't come home at 5am the next morning.

I decided I needed to discover the truth on my own. He works in technology and I knew that getting access to his phone or emails would be tricky; he'd always explained it was a necessity of his job to change passwords frequently.

In those early hours of the morning, I tried my luck with a few combinations and to my complete surprise, I was in his Gmail within five minutes.

I'll never forget how it felt to find those emails and photos. My face went hot and my heart began to beat out of my chest so hard I felt the pain in my ribcage. I couldn't swallow.

I was desperately trying to screen-grab the evidence but my hands wouldn't function and I dropped my phone several times. There were emails detailing their recent trip to Washington, while I'd been in Bali. There were countless pictures that he'd been emailing himself, some of her in bed.

I had no idea who she was but searched for her on social media and there I was confronted with the biggest shock of all: photos of the two of them from months ago, the seemingly happy couple. She'd tagged him with a whole new alias, another person. A stranger.

I sat on the bed. Everything was blurry. Didn't we get married just six months earlier? We'd been together seven years, and moving to New York was supposed to be our next chapter. I had always thought the world of him.

I sat there until the sun rose to fill the bedroom with an eerie new light. Eventually, I called a close friend who lived nearby, in a place on Hope Street. I'll always remember her sleepy words: "There's hope on Hope Street." I packed a few essentials and left.

Instead of confronting him directly, I emailed his parents back in Australia, explaining why I was leaving. I wanted him to get a shock, as I had. Then I emailed her. It didn't take long to get a reply and, as I'd thought, she had no idea he was married.

When he finally confessed, it didn't feel liberating, as I'd hoped. He sounded sad and desperate, like a child who'd let a prank go too far.

Three days later I moved the rest of my things out. It was snowing. It felt like the right moment to be starting over. •