Three years ago, I attempted to climb Snowdon, England and Wales highest mountain, for the first time.

I was unprepared for the experience, supremely unfit, and attempted to climb the mountain during appalling weather conditions with visibility limited to 10 metres.

The outstanding memory of the experience wasn’t the view (well there wasn’t one because of the cloud), and it wasn’t of getting to the summit. It wasn’t even the thrill and pride of conquering England and Wales highest mountain.

The outstanding memory of the experience was sitting on a large rock halfway up the mountain having a complete and utter meltdown.

I was cocooned in cloud, the rain was coming at me at an angle, not another soul nearby (who was stupid enough to climb a mountain in such adverse weather conditions), crying like a toddler who had fallen over and hurt their knee. In between heaving sobs, I loudly wept that I couldn’t do it, that I wasn’t good enough to climb Snowdon, that I was going to get lost and die on the side of the mountain.

I was that close to giving up.

But I didn’t – thanks really to the dogged determination of my boyfriend who basically dragged me kicking and screaming to the summit.

In the aftermath and all these years later – having climbed Snowdon three times since – I still think of that day in terms of that moment on the rock halfway up Snowdon. In many ways it is the defining moment that encapsulates my self-doubt. But I also look back on it with a deep sense of shame; that I let my private battle come to the surface in such an unsophisticated display of snot and tears. More than once I have berated myself and my weakness that I showed on that day.

For the vast majority of the time I leave this part of me hidden, away from public view. I do a pretty good job, I think, of keeping it a secret and giving the impression that I’m AOK. I try to keep my self-esteem in check. It doesn’t always work and those times my self-doubt lapses into low self-esteem. Trying to stay in control is frustrating, at times exhausting, and also lonely. It’s really only a small step to depression and a downward spiral to deteriorating mental health.

I’m one of the lucky ones though. For many people, the tipping point is more extreme, the downward spiral accelerated.

While self-doubt and low self-esteem are not mental health problems they are closely linked. And in a fast-paced, social-media obsessed world, I fear the prevalence of self-doubt and low self-esteem is on the up and potentially points to a growing mental health burden on society, as well as sapping the happiness out of us and putting goals and dreams on hold for “one day”.

Just look at some of the stats:

• More than half of 18-34 year olds feel that reality TV and social media have a negative impact on their body image
• Eight out of 10 girls will opt out of fundamental life activities because of low self-esteem
• 72% of girls say they are not assertive or confident in their opinions if they don’t feel good about the way they look
• According to the British Heart Foundation, 53% of people fear life is passing them by
• One in five people describe themselves as being lonely
• Anxiety disorders are now the most common mental illnesses in the USA
• 40% of working millennial women and 22% of men experience self-doubt at work
• Nearly one in five SME owners suffer from imposter syndrome – nearly half believe someone else could run their business better and nearly a third admit that feeling like a fraud has prevented them from taking their business to the next level
• 42% of Brits claim a lack of confidence deters them from applying for their dream job

In the past, I have been more than one of these statistics.

I would never have committed to solo walking 3,000km down the length of New Zealand if it wasn’t for the fact that I realised my self-doubt and my thoughts were instrumental in holding me back from doing something incredible. It was enough of a kick up the backside to buy a plane ticket.

Thinking back to that time on Snowdon and knowing how I have mentally beaten myself up over the years, I know it isn’t pleasant disliking yourself and believing you can’t do anything or that you’re not good enough.

No one should have to experience that – and certainly no one should feel it so bad that it morphs into a mental health problem. And furthermore, it should never hold us back from achieving our goals and dreams or stop us from being happy.

It’s for this reason that as part of my #WalkNZ adventure I’m fundraising for two mental health charities – Mind in the UK and The Mental Health Foundation of New Zealand. Both are actively supporting people with mental health problems and empowering people to take back control of their lives and their mental wellbeing.

If anything I’ve written here rings true for you or you just want to support the work of these great charities, then please donate – your donations are greatly appreciated and go some way to making someone’s life that little more manageable and the world a better and happier place. Who wouldn’t want that?

To pledge your support, please visit my fundraising pages for Mind in the UK here or for The Mental Health Foundation of New Zealand here.

Thank you – every little bit counts!