But behind the immaculate exterior lie a TV presenter working hard to keep the lid on a frightening secret threatening to derail her 25-year career.

‘’It only ever happened on air, and it was terrifying,’’ Johnston said, describing the crippling anxiety that consumed her for roughly 60 seconds of every prime time bulletin for three years.

The first time it happened she thought she was having a heart attack.

‘’My heart was a bass drum, I could hardly breathe … I stumbled through, took a huge breath and then after the bulletin I thought ‘what the hell was that?’ ’’ the mother of two told the Mercury.

It happened again the next night, and the next, and the next. ‘’It was every night, it was harrowing,’’ she said. ‘’I would come home and fall in a heap … there was lot and lots of tears.’’

Johnston would spend the drive to work each afternoon with a knot in her stomach, fearing the anxiety would again grab hold of her.

‘’The more I thought ‘Oh no, the only time I don’t want this to happen is when I’m on air’, that’s exactly when it would happen. It became like a self-fulfilling prophecy.

‘’Every night I would anticipate it, so I really feel that anticipation was the trigger for me.’’

Today she is embarrassed to admit she was ‘’that person who thought people who spoke of anxiety attack just needed to ’suck it up’’’. 

‘’I used to think anxiety was a hypochondriac’s version of stress, like people with a sniffle who claim it’s the flu. It’s not until you have it that you realise it really is debilitating.’’

Johnston was great at her job, one of the most well-known and well-respected faces in regional television. She was terrified her work colleagues, not to mention the thousands of viewers, would see through her shaky veneer.

Each night she would scrutinise the recordings of her bulletins and agonise over little signs she was convinced would give her away – the shaky voice or the extra deep breaths she used to gulp the terror back down into her stomach and out of view.

‘’My voice would rise an octave and that was always the giveaway,’’ she said. ‘’Sometimes I would have to wait a few days to watch it and I’d think ‘Oh god how can people not notice? It was so obvious to me, it was horrifying.’

‘’I did take my job seriously and I didn’t often make mistakes and I absolutely hated this thing because it wasn’t my doing.’’

Johnston ‘’wasn’t comfortable’’ with having anxiety so she followed her usual plan for dealing with adversity – attack.

‘’I got lots and lots of help straight away. I spoke to everyone, I went to a psychologist. That process was all about the tears and letting it out, but that wasn’t right for me. I was not sad, I was really cranky,’’ she said.

‘’Some people find that treatment extremely helpful but it wasn’t for me.’’

Johnston also shied away from medication and eventually came across a counsellor in the Illawarra well versed in anxiety disorders and helping people find a way forward.

‘’She gave me so many tips but distraction was the best one. I would distract myself in every way possible. I talked myself into thinking that if I didn’t have coffee after midday or carbs I would be right.

‘’If my heart was racing I would take Bach flower remedy, we went through litres of it,’’ she joked.

‘’One of the most common things people tell you is to focus on breathing, but live on air I just didn’t have that option. I could be halfway through and as my heart would race and I would lose my breath, I’d be like ‘what can I do, I’m live on air?’’

Clenching her fists and tapping under her desk sometimes helped change her focus. And with some creative sub-editing Johnston bought herself some time.

She would separate her live reads to give herself a chance to breathe while vision rolled. She would rewrite paragraphs to shorten her pieces-to-camera so to lessen the chances of ‘’total humiliation and embarrassment’’ in front of thousands of viewers.

Her techniques worked for her, and by the time she resigned from WIN TV in February this year, she hadn’t had an attack in over a year.

‘’I wasn’t prepared to walk away when it had me pinned,’’ Johnston revealed. ‘’And I’m so glad I didn’t, I got through it. My decision to leave had nothing to do with it and I’m really glad about that. ’’

Johnston describes herself as a work in progress – and while she will continue to avoid underground carparks – life post WIN is peaceful and anxiety free.

‘’I’m not someone who sits back and accepts ‘Oh well I’m anxious and claustrophobic’,’’ she said. ‘’ It really annoyed me, it was nonsensical to me.

‘’It sounds so cliche but I want people to know you can overcome it. I feel like a weight has been lifted, I feel free.’’ She wishes she could pinpoint her turning point. ‘’Then I would really have something that would be helpful to other people. That could make a difference.’’

Johnston will be be part of a mental health forum for Studio 10 and guest panelist on May 31. 

For anxiety support www.beyondblue.org.au