She'd go on to suffer migraines throughout her childhood, and early adulthood, but it was in her 30s that they became chronic - and crippling.

At one stage the Kiama resident was suffering up to 28 migraines a month. So severe were the attacks, she'd temporarily lose her ability to speak or see, vomit uncontrollably, even end up in convulsions.

She lost count of the times she was hospitalised - sometimes for several days - as medical specialists tried their best to ease her symptoms, and work out what exactly was going on.

She tried everything to ease the pain, consulting countless medical and alternative health specialists - ultimately ending up on a dangerous and debilitating cocktail of opioids, which she despised.

Then four years ago, after yet another hospital stay, she found herself down at the beach, and being drawn into the ocean. And that's where she finally discovered her panacea.

"People have no understanding of chronic migraines - it's not just a bad headache," says Chrissy, now 47.

"It started to get chronically bad when I reached my 30s. It's meant that my two boys, now 12 and 15, have spent most of their lives seeing me lying in my bed for days on end, on occasions having to hand feed me as I've been too weak to get up.

"There's been no family holidays as I can't go too far from home, no birthday parties as I just don't know how I will be on any given day.

"I'd need to be hospitalised regularly, where they'd check me for strokes and aneurysms because I was convulsing, because I had no speech.

"But I didn't tick any boxes, it's not a condition anyone can see. I've been accused of being an opioid-seeking junkie - and at one stage was taking 18 medications a day to deal with the pain.

"Then four years ago, I ended up in hospital again. And when I was discharged, I was still so drugged that I was shaking and I asked my husband to take me to the beach.

"I got in the water and just had an urge to swim out. I went out further and further, and the deeper I got the more beautiful it became.

"That's when I realised that the screaming pain in my head didn't hurt anymore."

After many years of searching for answers, Chrissy was formally diagnosed in her 30s with severe chemical sensitivity - which means certain chemicals, certain perfumes, could trigger migraines.

Yet the smells, sounds, sights and feel of the ocean consistently ease her pain, like no drug or therapy has ever been able to.

Cold water therapy has its roots in ancient civilisations, yet it was Dutch extreme athlete Wim Hof who has popularised its use in recent years.

Wim Hof, now in his 60s, got his nickname 'The Iceman' by breaking a number of records related to cold exposure. He developed the Wim Hof method, which incorporates cold therapy, breathing and meditation to bring health benefits including increased energy, better sleep, reduced stress. The method has also been associated with an improved immune system, which has a positive effect on fighting the inflammation associated with migraines.

Chrissy knew none of this when she swam out to sea in the cold waters off the coast of Kiama that day, nor had she heard of 'The Iceman' when she progressed to diving down even further.

But she sure reaped the benefits, and continues to swim in the ocean and enjoy freediving alongside seals, rays, even the odd shark.

"Some nights I feel the pain building in my head again, but I know that first thing in the morning I'll get out in the water and the pain will go away," she says.

In the past year Australian champion freediver and instructor, Adam Stern, has been her trainer - and her inspiration.

Chrissy had been studying one of his online courses before she bumped into him on a diving tour.

"With his support, I can now hold my breath for three minutes, 30 seconds and can freedive to a depth of over 30 metres."

While Chrissy has only discovered the benefits of cold water therapy in the past four years - the call of the ocean has been with her for a lifetime.

"When I first got into the water, it took me back to when I was little - my dad was a freediver, my mum was a swim instructor and I used to swim competitively in ocean pools," she said.

"I've never lived more than two minutes from the ocean ... so when I first started swimming it took me back to those early days, it made me remember who I was."

Chrissy's story is timely - with June being Migraine Awareness Month. The theme for 2021 is 'Your migraine, your way' - focusing on how sufferers can take control of their migraine journey. And Chrissy is a great example of that, says her neurologist Associate Professor Dennis Cordato.

Professor Cordato, a senior staff specialist neurologist at Liverpool Hospital, has been treating Chrissy for several years.

"Migraine treatment is not just about pharmacological treatments, it's about taking a holistic approach to health and finding what lifestyle changes can make a difference.

"For Chrissy ocean swimming has been key to getting her migraines under control, which has helped her get balance back in her life.

"We don't know exactly how it works ... But Chrissy's story shows people with chronic migraine that they don't need to sit and suffer, that there are treatment options or lifestyle changes that could help.''

Chrissy still sees Dr Cordato every 12 weeks but is down from 18 medications to eight.

"For many years I was so sick I just wanted to die, but I knew that wasn't an option. Even at my worst I always believed in hope and just kept going.

"I hope my story, my journey, may help others."