For more than a decade, Kate Seselja lived a double life. It nearly destroyed her family.

It was January in Canberra — that humid stretch of the year when the festive high has worn off and the reality of the New Year sets in. Kate Seselja was meant to be running an errand for her husband's business.

Instead, she found herself sitting in the corner of a local venue, tears streaming down her face. Around her, the rhythmic whirring and artificial cheers of poker machines provided a cruel soundtrack to her breakdown.

"I sat there for hours, just pregnant, crying," she told Mamamia's No Filter.

At the time, Kate was pregnant with her sixth child. Her mind was trapped in a dark, impossible calculation: "[I was] trying to figure out how to take my life but not harm my child."

Her phone began to ring. The screen lit up with her husband Phil's name.

"I didn't know what to say," she recalled.

Kate had a secret — one that cost her half a million dollars and was about to blow her entire world apart.

Listen to Kate Seselja's chat on No Filter. Post continues below.

For 12 years, Kate had been living a double life. To the outside world, she was a capable, busy mother of six. But behind the scenes, she was trapped in what she calls a "mental hijack."

It began in 1997, when she was just 18. Her then-boyfriend introduced her to the machines, offering the classic "just put $20 in and press this button" advice.

"A couple of presses in, I won nearly $1,000 and my heart was beating out of my chest," Kate said. "Nothing like that had ever happened to me before."

She called it her "beginner's misfortune".

From that moment, the "ping" of the machines became a siren song. Suddenly, she saw them everywhere — in every pub, at every club, calling to her. And her brain was desperate to answer.

When she met Phil a few years later, she thought she'd found her exit. He was "wholesome and happy and joyful" and represented a fresh start.

Soon after, they married and moved to Canberra, and for 18 months, the fresh start fairytale held.

But addiction is a patient predator. It waited until Kate was at her most vulnerable — a new mum, building a house, living with in-laws — to strike again. And it happened in the most mundane of places: a mothers' group meeting that had been moved to a local club.

"It re-triggered my body and mind in a way that I was not prepared for," Kate said.

Kate as a teen. Image: Supplied.

The spiral was fast. Kate lost $30,000 in a single month.

In her mind, the logic felt foolproof.

"Do you remember that time you put $20 in and you won this much? Well, you know you could get the house built faster and faster…. I started with $100 and then $200, then $1,000, then $10,000, then $30,000 in a month."

When she finally confessed to Phil, she was so consumed by shame she wanted to die.

"Had I not been pregnant at that point, I don't think I would be here," she said.

"I think it's amazing that the two points in my life where I just couldn't take it anymore, I actually had life inside me, keeping me here, and I'm forever grateful for that."

To her shock, he didn't scream. He just asked, "So you're not leaving me?"

But while Phil was ready to move forward, the addiction wasn't finished. For the next eight years, Kate lived on a loop of abstaining, stressing over bills and then returning to the machines as a solution.

"I created this problem. I've got to fix it," she recalled thinking.

"All of my money would go into the machine. I didn't eat, I didn't drink."

Sleep offered no reprieve from the stress.

"I'm having dreams about the machines in my sleep, I'm hearing the sounds. It was torment."

The shame became a prison. Kate "hamstrung" Phil, telling him, "If anyone ever finds out about this, I will kill myself."

It was a deadly pact of silence that allowed the addiction to thrive in the dark.

Kate and her family. Image: Supplied.

A $12,000 low.

At her lowest, Kate lost $12,000 in a single session. She'd walked in with $1,000; the other $11,000 was withdrawn directly from the family mortgage at a bank across the road.

The money was gone in an hour.

"I was so done, so mentally, physically, emotionally exhausted," she said.

"I couldn't keep holding up the facade of I'm okay anymore."

That January day in 2012 was the final floor. When Kate finally answered Phil's call, she expected anger. Instead, he simply said: "Please just come home."

"You're not you when you're in the grip of gambling harm," Kate said. "You may look like you… You're being driven by something you don't understand."

The next morning, he drove her to a counsellor.

Kate was sceptical, planning to just "play along" until the baby was born and then complete her plan to end her life. But the counsellor didn't ask about the money. She asked Kate to name 10 things she liked about herself.

"She could see how destroyed I was," Kate said.

"It took me a week to come up with the list… I realised that every time somebody paid me a compliment, I never let it penetrate my skin because I felt I wasn't worthy."

Bit by bit, Kate rebuilt herself "from the ground up." She stopped seeing herself as a "problem gambler" and started seeing herself as a person who had been harmed by an industry designed to addict.

Hearing other people share their gambling addiction stories was the reassurance Kate needed that she was alone.

"I think I just exhaled for the first time in 15 years, like it was amazing," she said.

'Loss limits, not lost lives.'

Today, Kate is a fierce advocate, campaigning for "loss limits" to prevent other families from losing their loved ones and futures. She wants others to understand the shame doesn't belong to the mother crying in the RSL, but to the industry that "mousetrapped" her.

"It is insidious," she said.

"The shame in this scenario belongs on the knowing perpetrators of harm. This industry that created products designed to addict, governments who have enabled it for decades."

While Kate has been able to turn her struggle into something bigger, she knows some families never recover from the ruin.

"The industry doesn't just weaponise shame against the individual. They weaponise shame and play with it in families," she said.

"They make families hate the person who gambles instead of understanding that, as a family, you've been harmed by this industry. You need to direct that where it belongs."

For those still in the "whirring" loop, Kate's advice is simple: understand that this has happened to you, it's not who you are.

"They use people to extinction," she said. "Had I not been pregnant, I would have killed myself… they would have kept exploiting people. My family would have struggled, and no one would have known."

Now, everyone knows. And because of Kate, they know there's a way back.

If you or someone you love is struggling with gambling addiction, help is available. For support, please call Gambling Help on 1800 858 858 or visit Gambling Help Online.

If you find yourself needing to talk to someone after reading this story, please call Lifeline on 13 11 14.

Feature image: Supplied.