LOSING your only child is an agony most parents can’t even bear to contemplate.

But, last July, on a sunny Saturday morning, Anne-Marie Cockburn was forced to when her 15-year-old daughter, Martha, suffered a cardiac arrest after, it’s believed, taking what she thought was ecstasy.

Instead of letting the shock of such devastating loss destroy her, Cockburn coped by writing about her grief, putting pen to paper within hours of Martha’s death.

Six months on, her harrowing memoir of how it feels to lose the child you’ve built your world around, has been published. Her raw grief is laid bare on every page of the book, called 5,742 Days to mark the short time Martha was alive.

“I was writing within a few hours,” she recalls. “I think it was the way I reacted to the shock – I was manically trying to make some sense of what was going on.It is a way of saying goodbye to my only child, the only child I’ll ever have. It’s my journey through the early days of my grief – it was a lifeline for me; it helped me get out of bed in the morning.”

Before Martha died, Cockburn, 43, ran writing therapy workshops for stress, anxiety and depression, so it’s not hard to see why she turned to writing as a way of coping.

There have, of course, been floods of tears, despair and disbelief since Martha’s death, but also laughter as Cockburn remembers the “beautiful life” that her daughter lived.

Although Cockburn’s strength and stoicism does run a thread of hope through the tragedy, the agony of her experience is clear right from the opening page.

“My 15-year-old daughter died yesterday,” she writes bluntly. “I watched them try to save her. They pumped her chest and drilled something into her shin, but I knew she was already dead on arrival at the John Radcliffe Hospital in Oxford.

They elevated her arms, but I don’t know why. Her eyes were half open and she was way beyond the clouds and stars already.”

IT’S a waking nightmare that must have been especially hard for Cockburn to deal with, as not only was Martha her only child, but she had no partner to turn to for support.

She insists that needing to cope alone has made her stronger.

“I’m a single parent and I’m used to having to get on with it myself,” she declares. “It was just Martha and me; I was mum and dad. Now, in the middle of the night, I don’t have another shoulder to cry on, it’s just me.

So I found this inner strength and thought I just had to get on with it.”

She even came up with a word to describe her situation: “smothered,” which stands for single mother of expired daughter.

“I’m not a widow, I’m not a divorcee, so I decided I was smothered,” she explains. “Single parents have to be very strong – they’ve got a lot to contend with, and that strength in my parenting has enabled me to find the strength again in my bereavement. In the depths of despair, an incredibly acute sense of survival kicks in, and that’s certainly what happened with me.”

Her book charts the days leading up to what would have been Martha’s 16th birthday on October 30, 2013, when Cockburn and around 30 family and friends gathered to release water lanterns at 6.41am, the exact time of Martha’s birth, at the Oxford lake where she collapsed.

There is an ongoing police investigation into what happened to Martha, and the inquest into her death has not yet been concluded.

But Cockburn has already written 11,000 words of her next book, in which she hopes to tie up loose ends.

THIS second book may well be written in a different tone to the first. Cockburn says that six months after Martha’s death, the pain is a little gentler.

She could perhaps choose to be bitter or angry about what happened to Martha, but there’s certainly no sense of such emotions in the book.

“It’d be such a shame if I became bitter and twisted, because it doesn’t change the end result, does it? It doesn’t bring her back, so I choose to be optimistic.

“You cry your way through the hard days, and you have your moments where it tears you to pieces, but you have other moments where you feel you’re okay.

“I know I’ve got a long way to go, but I’m determined to keep seeing life with a positive perspective.”

Cockburn has started a charitable trust, called What Martha Did Next, run by the Oxfordshire Community Foundation, to help raise awareness of what happened to Martha through talks in schools. Cockburn believes that this charity, and her book, can get through to teenagers in ways that nagging them won’t.

“If parents are worried about their own children, then my book will bring things home to them,” she says. “I can tell them this is what happened to me, but I’m quite rare, so I don’t think parents need to be worried about yet another thing.”

She advises parents to talk to their children honestly. “Admit what you did when you were younger, because it helps them understand they’re not the only ones who make stupid decisions.”

Finally, the “smothered” mum says she hopes people are touched by her book, and adds: “I hope it helps people, because it’s certainly helped me.”

  • 5,742 Days, by Anne-Marie Cockburn (Infinite Ideas, £8.99).
  • To donate to What Martha Did Next, visit justgiving.com/ WhatMartha didnext