This week marks a somewhat difficult landmark – on Thursday, I've officially lived longer without a father than I have with one.

My Dad's death, three days after my 21st birthday, wasn't a surprise.

He had been dying, painfully slowly, since I was 14 and I had already been summoned home from university twice to say my goodbyes, only for him to rally at the last moment, clinging on to a life that by that time simply wasn't worth living.

We didn't have a telephone in my shared student house, so police officers had to knock at my door to give me the news that I had a small window of opportunity to race home from Liverpool if I wanted to see my Dad one last time.

I remember walking up the stairs to pack a bag and thinking, ridiculously, 'this is the last time I'll walk up these stairs when my Dad is still alive'.

Similar thoughts followed me on the drive home: this is the last time I put petrol in my car, the last time I pass the sign welcoming me to Robin Hood Country, the last time I pull into the hospice car park, the last time his hand will be warm in mine.

Back in Norwich, the drill was familiar. I was to say anything I felt I needed to say, make my peace, reassure my Dad that it was fine to let go, understand that this time, it really was goodbye.

I can't remember precisely what I said, although I do remember promising that I'd look after my Mum and that I'd try to make him proud – really, though, what do you say in that situation? It's not as if there's a manual to consult or a checklist to refer to.

I've never been any good at public speaking so I'm fairly convinced I gave a lacklustre performance - I'm far better behind a keyboard - but I think it's probably bad form to bring a keyboard as a prop when you're visiting someone's deathbed.

We had the opportunity to stay with him but chose not to: we were both convinced that our presence would elongate the process, that by leaving we were offering tacit permission for him to die quietly, without an audience jumping up every other minute to check whether he was still breathing.

The next morning, we sat down for breakfast together before going back to the hospice. At 9.13am, the phone rang, I heard my Mum saying just a few words before coming back to sit at the table.

'Your Dad's just died,' she said. There were no tears from either of us: when someone is as desperately, miserably ill as he was, death wasn't the very worst thing that could have happened, it was the very best.

At the hospice, staff encouraged me to look at my Dad one last time and told me they thought he'd 'hung on' so that he lived until I was 21 (the implication being that he would have thought it somewhat uncouth to die on my birthday, not quite the 'key to the door' he received on his 21st).

I wish I hadn't: he looked mildly shocked; as if something unexpected had taken him by surprise.

My Dad died on Friday the 13th: unlucky for some, particularly unlucky for him, although if you're going to go, you might as well outdo a cliché while you're at it.

Diagnosed with Multiple Sclerosis seven years earlier, my Dad also had terrible luck when it came to a condition that often allows those with it to live a fairly normal, long life.

The strain he had was vicious, fast-moving and devastating.

Within a few years he was bed-bound, his eyesight was failing and he was reliant on my amazing Mum's round-the-clock care which she offered up despite the fact that he was an absolutely appallingly-behaved patient – the woman had the patience of a saint.

He had made the unilateral decision that I shouldn't be told about his condition until after I'd taken my O-levels and luckily for me – being a selfish teenager – I simply attributed the pall of gloom that hung over my house as another illustration of how life Just Wasn't Fair.

When I was finally sat down in the living room and the news was delivered, I reacted by thinking about how it would affect me: when you're 15, everything is about you and having a disabled Dad certainly Just Wasn't Fair.

I spent a lot of time away from home, leaving my Mum to do everything, and then scarpered to university where my newfound anonymity meant I didn't have to tell anyone whatsoever what was happening: about the lack of support from Social Services, about the rails and ramps that now dominated the house, about the fact that my Dad was disappearing before my very eyes.

During holidays, I sometimes had to steel myself before visiting him in the annexe we had adapted so that it could accommodate a hospital bed: before he was ill, he was a sport-obsessed, sharp-minded blokey bloke.

The illness robbed him of practically everything – although he gamely smoked until almost the very end and, despite being rendered practically mute, had a trademark look he'd throw anyone who annoyed him: I've inherited it, along with his nose, his stubbornness and his love of words.

He died a few months before I graduated from university, a year before I became a journalist and five years before his first grandchild was born: that he missed all of these things plays on my mind often.

A former head of an English department at a Norwich school, Dad's dream had been to work in publishing and I'd have loved for him to know that I would make a living through writing – but nowhere near as much as I'd have loved for him to meet my daughter and my son.

He taught me to ride a bike but was never well enough for me to drive him in a car (probably a blessing in disguise), he taught me to read but never saw my work published, he taught me to roll cigarettes, but that's definitely not something I should boast about.

I'm sad that the most enduring memories of my Dad are of him being ill, being angry and feeling trapped: I try to remember better times, but it's difficult when the bad times were so very, very bad.

That said, I'm incredibly lucky to have a wonderful Mum to have shared the important landmarks that my Dad missed and who taught me more about sacrifice, loyalty and love in seven years than I could have picked up in a lifetime.

Having lived through 20 anniversaries of Dad's death, I doubt the 21st will feel any different. But the day after the anniversary, the moment when I've officially been Dad-less longer than not, that will be something new. RIP Dad: I'm still looking after Mum – not that she needs it – and I hope I would have made you proud. I love you.