Excitement, anxiety and sheer panic - that's the mix of emotions I was feeling this time last year when I was days away from running the London Marathon.
Running this event was something I'd felt an overwhelming urge to do for many years. But when my eldest sister, Joanne, unexpectedly passed away in 2004 following a life of severe epilepsy, my casual interest in running became a coping mechanism for unbearable grief. Putting on my earphones and letting my legs take me wherever I wanted helped vent my anger, frustration and sadness over the loss we'd had. Running was my release.
After running The Great North Run and various 10K events, my appetite for doing something 'bigger' was still there. I wanted to keep my sister's memory alive but also further raise the profile of epilepsy charities. If I could gain a place in the Virgin London Marathon in support of Epilepsy Research UK, it would first of all help fund research projects on adult and childhood epilepsy every year. Secondly, it could also help them make developments in drug therapy and medical scanning and enable them to reach a better understanding of the causes of this somewhat misunderstood condition. Meanwhile, I could of course, keep Jo's memory alive.
The Fundraising Officer, also called Jo, must have sensed my sheer determination when after four or five years of applications I'd still been unsuccessful. Then in October 2013, I received an email saying, 'I'm able to offer you a place!'
What followed was six months of relentless training and physio sessions. Fitting a training programme around my work, relationship and social life became the biggest challenge yet.
The worst bit was forcing myself to run in all weathers. On a few occasions, I ran four or five miles from my flat, to find myself stuck in freezing downpours with no money or bus pass to get home. I quickly learned from that mistake.
As it began to warm up, the training - in some ways - got harder. I'd spend Saturdays doing circuits of Hyde Park while the sane people in London basked in the sun with jugs of Pimm's. My partner would call me up to reassure me that I wasn't entirely crazy for doing this.
During my six months of training, I tackled recurring Iliotibial band syndrome, lower back pains, shin splints and many pulled muscles.
Luckily I found an amazing sports therapist - Laurie Cooper - at Hub Health in Clapham. She helped me physically - and as she was running the marathon - mentally, too.
As the weeks passed, the notion of ever getting to 26 miles felt increasingly daunting. Writing a blog - The Reason I run - and scrolling for motivational quotes on instagram and Pinterest became my pastime.
On Sunday 23 March, I broke through the wall of doubt and ran 22.54 miles. I couldn't believe it. I'd nearly run the whole distance. But on the morning of the event, I woke up feeling groggy and in a state of self-doubt. I wrapped my legs in KT tape, ate a ridiculous amount of calories and set out with no idea how that day would pan out.
The high point was seeing my fiancé and my friends at around 11 miles in. Crossing Tower Bridge surrounded by TV cameras and throngs of people was also breathtaking.
The low point? The seven or eight mile route that takes you around the Isle of Dogs and Canary Wharf. That's where I really had to dig deep for mental and physical strength because it's here you think it's nearly over, but the reality of it all gives you a great big slap in the face.
We emerged out of the tunnel on Embankment to an overwhelming surge of shouting, screaming and applause. My kneecaps were 'popping' and the muscle spasms had reached excruciating levels. I was inches away from hitting that wall.
Somehow, I found one last morsel of strength to complete the 26th mile. Spotting my parents, fiancé and best friend with smiles on their faces at the end was that last push I needed.
I raised nearly £2,000 for Epilepsy Research and a few weeks later, I was invited to the House of Commons to meet people who had been affected by the condition, charity members and the lead researchers behind the organisation.
I also met a girl who'd undergone successful brain surgery to help cure her seizures. That could have been my sister, but she was deemed unsuitable for surgery, as there was a high chance it could have left her severely brain damaged.
It doesn't always feel like it, but there's a silver lining in this cloud. Knowing that we've helped people like that young girl lead a better life, just confirms how important charity events like the London Marathon can be.
As I watch runners stagger over the finish line this year, I'll feel proud I waved the flag for such a worthy charity in my sister's memory. I'll also feel a knowing sense of excitement for them. Because when you cross that finish line and realise what you've achieved, well there's no feeling quite like it.
This blog is an edit of a piece on OhSoLondon.com. Follow @LucyAMcGuire@EpilepsyRUK and @OhSo_London on twitter
For more information about Epilepsy Research UK, visit their website: EpilepsyResearch.org.uk.