'The comment from my boss that made me quit my job without a back-up plan.'

As I looked at the collection of supplements and 'calming tonics' on my bedside table, the realisation hit me.

Over the previous 12 months I'd spent in my position at a well-known Aussie corporation, I'd somehow come to rely on Ashwagandha, magnesium, CBD oil and a deep-breathing regimen just to get myself up and out the door every morning. 

For a while, I'd told myself it was perimenopause. I'd upped my dose of antidepressants. I was having near-weekly panic attacks and I felt as though all the confidence I once had as an accomplished and well-paid executive had been drained out of me like a deflating helium balloon left over at a kid's party.

Staring at my little collection of calming supplements, the lightbulb went on. It wasn't normal to have to put in this much work just to keep the dread at bay. Something was very, very wrong - and that something was my boss.

When my boss - let's call him Toby* - hired me for the role, I thought it would be a good fit. He was full of promises about making the role my own, and while I could tell he wasn't the kind of person I'd enjoy spending time with on a personal level, he seemed professional, reasonable and switched on.

This quickly deteriorated a few months on, when he decided he wasn't getting the results from me that he needed. Despite a good yearly review where he declared that I was meeting his expectations, Toby soon began displaying some red-flags.

Watch: The common signs you have a toxic boss. Post continues after video.

First, he believed the acknowledgement of Country we do at the beginning of meetings was 'a waste of time' - something he stated openly to our entire team. My gut twisted at his ignorance.

Next, he targeted a junior staff member in a meeting, telling the entire room that she was 'sh*t at her job'. He insisted I send him projects I was working on for progress updates, and when he received them, he simply responded 'not a chance', without any feedback or guidance as to how he wanted me to proceed. 

Coming from a management background where I successfully led a team of hundreds, I knew this wasn't best practice and that it was incredibly toxic, but what shocked me was how quickly I began to second-guess myself.

The impostor syndrome that had always lurked under the surface began to rear its ugly head, telling me the only reason I'd been so successful at my last job was that I'd had a better team beneath me, making me look good.

In spite of the fact that my own team was doing excellent work in this new position, Toby would always find something wrong with what we produced. 

On one occasion, he called me into a meeting to tell me that my role, along with my entire team, was a waste of company money.

Fuelled by the top-down toxic culture, other employees at my level began turning on one another. A colleague I thought I could trust once threw me completely under the bus in a meeting, telling Toby that the reason her work hadn't been delivered was because I'd held her up. It wasn't true, but the constant environment of fear overrode her sense of right and wrong. 

My entire career, I've valued open communication and peaceful conflict resolution. I'm someone who believes in taking accountability and maintaining good professional relationships, so finally, a few months ago - after my bedside table full of supplements sparked the realisation that something had to change - my first step was to raise some of the issues I was having with Toby, in the hopes that we could work towards a more productive environment.

His response was the final nail in the coffin.

Toby believes that 'constructive tension' is the best way to run a team. He constantly drones on about it, believing that a 'healthy' amount of competition between staff, even conflict, will drive the best results. 

When I spoke to him about how I was feeling, his response was to tell me that the constant, gut-churning anxiety his leadership was creating in me was actually doing me - and everyone else - good. When I pointed out that another leader had been aggressive with his team, garnering several complaints, Toby's response was "yeah, but he produces good work."

The next day, I handed in my resignation without another job to go to. 

In a world where employee burnout rates are through the roof, people are more stressed than ever before and my physical and mental health are suffering. This bigoted, aggressive man trying to tell me that I needed to feel more stressed at work for his benefit was the tipping point.

My confidence has taken such a hit over the past year that I knew I needed to stop further damage, regardless of the cost.

Almost immediately after handing in my resignation, the crushing anxiety I'd begun to worry was a permanent fixture in my chest began to ease. As colleagues found out I was leaving, they began to open up about their own experiences with Toby, and how desperately they wanted to leave as well.

I'm not sure what my next move is going to be, or where I'll end up. I was lucky enough to have some savings to rely on while I lick my wounds and try to rebuild my mental health, and carefully (oh, so very carefully) choose where I plan to work next.

But the fact that I can be staring down the barrel of spending Christmas unemployed, and it is still causing me only a fraction of the anxiety that working there was, is all the information I need to realise I've made the right decision. 

As a bonus, I've barely had to touch the Ashwagandha since I left. 

As told to Bek Day

*Name has been changed for privacy.

Read more of our articles about workplace:

• Modern Etiquette: The 23 workplace rules you're definitely breaking.

• 'I thought coercive control only happened in relationships. Then I met my boss.'

• Jessica was relentlessly bullied at work for 3 years. It landed her in hospital.

Feature image: Getty.