'When I landed my dream job, I was hiding a dark secret. It almost killed me.'

On the outside, Sarah Hussein had it all. She was working her dream job as a detector dog handler at Perth Airport, had a close-knit family and owned two houses.

But Sarah was harbouring a dark secret. She was a high-functioning meth addict.

"I always had the idea I could fix it and get myself out of it," the 39-year-old told Mamamia.

But that's how the vicious cycle continues and eventually, Sarah's double life came crashing down — hard.

It started as a recreational habit after Sarah was offered ecstasy on a night out. When that wasn't available one weekend and someone offered her meth, she thought, "What's the harm?"

"That was the beginning of the end," Sarah said.

"I was a high-functioning addict for many, many years and it all just avalanched and I lost everything in two months."

Watch: Jackie O opens up about drug addiction. Post continues below.

Sarah hid it well in the beginning, but slowly the cracks started to show.

"I lost so much weight. Anytime anyone tried to bring it up I'd just turn it back on them and say, 'How dare you? You think I use drugs?' Then I pushed them away," she said.

"My close friends and family saw through the life I was trying to project, so I tried not to see them."

At work, Sarah found excuses for being late and unfocused. Sometimes she would sleep through entire shifts.

"I was meant to start at 4am and I'd wake up at 10am and have all these missed calls," she said.

"I knew I was addicted but I thought I could get on top of it."

Sarah hopes to inspire others to turn their lives around after struggling with addiction.

The wake-up call: "I thought I killed someone".

Soon enough, Sarah was missing mortgage repayments and bills. Then everything imploded.

"My house got repossessed, I got fired from the airport, crashed my car and didn't have insurance. My dogs, who were my world, passed away within days of each other.

"That was all within two months. I was left sitting there going, well what the hell just happened?

"Someone warned me, 'I know you're doing well now but it'll all come crashing down' and I was like, 'Eh, I'll be right' and then I realised there was no digging myself out of this."

The car crash was a major wake-up call for Sarah. She fell asleep at the wheel and drifted off the road.

"I woke up a split second before I hit… I was drifting off the road all the time," she said.

Luckily, Sarah was okay and had crashed into a parked car, but at the time, she didn't realise.

"I thought I hit a moving car… I thought I killed someone," she said.

Sarah realised she needed help and checked herself in to rehab — a decision that was welcomed by her fed-up family.

"I remember being so scared to tell my dad and admit I was using… He just said, 'Thank God… we were waiting for you to finally want to go yourself'."

Sarah had to work to rebuild her relationships but says she's finally in a place where she's proud of herself again.

"I am proud of myself for the first time in a long time."

When Sarah looks back on her time in rehab, getting off the drugs was the easy part.

"It was all the guilt and shame in my head. I can see why you use again, because you don't want to have those feelings," she said.

"I was absolutely disgusted with myself. I had to work through that and I still am now today."

Once she left, Sarah's dad gave her a job to keep her out of trouble.

That was five-and-a-half years ago. Now, she's the co-founder of virtual reality training solutions company Industrial Metaverse, which she runs with her dad.

She's worked to regain the trust of friends and family and is happy with her life.

"It's taken a long time and the guilt and shame is still there, but I'm working through it. I am proud of myself for the first time in a long time," Sarah said.

She hopes to inspire others to turn their lives around, and to know that rebuilding after addiction is possible. She also wants to help change the stigma surrounding addiction, and raise awareness about how difficult it can be to escape without the right support network.

"I want to give hope to someone that you can do something with your life," she said.

"When I was in rehab, you sort of think that's the end. I didn't think there was any chance of having a decent life.

"I hope someone will see this and realise it's possible. Just keep putting the steps forward, even if they're little ones."

Feature image: Supplied.