We’ve just come home from looking at the Turner prize nominations at the Baltic centre, just round the corner from where we live in Gateshead: Hattie, our three year old, stroppy as usual; Martha, six, floated around; Ed, eight, was loud in his disarmingly exuberant attitude towards life in general. Roger and I enjoyed the art, but cast longing glances towards the cafe, hankering for coffee. Just an ordinary weekend family outing – but when you’ve survived a life-threatening cancer, as I have, nothing ever quite feels ordinary again.

I’ve had a rare, aggressive form of non-Hodgkin’s lymphoma. When they found it, four years ago, I was 32 weeks pregnant with our third child.

The diagnosis came out of the blue, if you don’t count the months of terrible itching, exhaustion and excruciating upper back pain that were repeatedly put down to the niggles of pregnancy. I was 38, fit and healthy, and had sailed through the previous pregnancies with nothing more to worry about than morning sickness.

First, I saw a lung-cancer consultant, though I don’t smoke. all that morning, Roger and I stared at day-time television without speaking much at all. I knew we were going to be told something terrifying – and talking was impossible. We went in, only to be told that I did not have lung cancer – I had a blood cancer. Another set of doctors arrived. I remember laughing and making a silly joke. they said I had about three weeks to live. Then they left us alone in the office.

I was diagnosed on a Friday, and told that on the Monday I would have to deliver our baby, who was exactly 32 weeks. I then needed urgently to begin what would be nearly a year of hardcore treatment: in-patient chemotherapy, dripped through a Hickman line for 72 hours at a time; a stem-cell transplant so brutal it carried a mortality rate of its own and, finally, radiotherapy. they were throwing everything at it, as the consultant said, to try to save my life. I think the enormity of it all didn’t hit me for a while.

Today, I look back and wonder how I coped. Hattie was born by caesarean section, because I wasn’t strong enough to go into labour. she was rushed off to special care, weighing a sturdy 4lb 9oz, something all the nurses exclaimed at. I was proud of her good weight: I had grown a healthy baby, a source of deep comfort when I was fading fast.

We were told that she might not cry when she was born as she was so small, but she did. I remember hearing that strong little cry and holding it inside me, as she was taken away and I was taken into recovery.

That was three years ago. Hattie stayed in special care for eight weeks, and, after a scary start, pretty much went from strength to strength. I started my first round of chemotherapy a week after she was born. I shaved off my long hair and the rest fell out, as predicted. I wanted to bury myself into my baby and shut the world out. Pretty much all I wanted to do was breastfeed her, but Hattie was covered in tubes in an incubator. for a week, I couldn’t even hold her, and anyway the chemotherapy was toxic enough to throw me into immediate and permanent menopause.

Trying to ignore that overwhelming need to feed her is a memory that can stop me in my tracks to this very day. And the other two? they were so little at the time that they got on with things. Martha, then two, was suddenly no longer the baby, no longer the only girl, and every time she saw me I had that blasted baby clamped to me, trying to get enough of her. Ed, very bright and sensitive at four, would ask me directly if I was going to die. “I hope not, I’m fighting not to,” was the best, most honest answer I could give.

They coped with living in a family that had stumbled into chaos and desperate fear. they had a mother who tried to do everything for them, refused to spend time in bed, then collapsed into fits of tears, or suddenly screamed in terrible anger and viciousness to anyone too close at the wrong time. my own mother turned herself inside out trying to help and (with Roger) bore the brunt of my fear. I thought I was going to die. I really thought I would not see my kids grow up. I had to make plans for that, and I hated everyone around me – even Roger and the kids, at times – for the fact that life would go on for them.

I sure as hell raged at the dying of the light. it truly wasn’t dignified at times – much as I’d like to pretend that it was.

That terror sat upon my shoulders, and sat in my stomach like a dead weight. Some days I couldn’t move for the paralysing clump of it. Aged 39, I found the early and extreme menopause upsetting and an assault on my sense of self. The side effects are so much more than not being able to have more children. Reaching this stage of life a good 15 years before I had expected, before it had even crossed my mind to consider it an issue, can make me feel resentful and even angry.

I nearly died when I had my stem-cell transplant, and with a battered immune system spent the first year after treatment ill with shingles, tonsillitis, sinusitis, swine flu and any number of other tedious, mind-numbing complaints. But as it turned out, I survived. Amazingly, I’m still here. The treatment worked. Now I have to come to terms with the idea of living again, which is strangely disorientating, and I have learned that many others in my – happy, lucky – situation struggle with the problem as much as I do. It’s really very strange.

I’m back at work – I went back in September and teach English part-time at a busy high school. I’m well, and coming up to three and a half years in remission. I have to get to five years to be considered cancer-free, and still have four-monthly check-ups. If I get a mysterious pain anywhere, it takes barely half an hour for me to feel something like blind panic, because the cancer can return in any organ. But day to day, the cannonball of anxiety in my stomach is for the most part absent.

As a family we are healing too. We talk about the time I was ill, the time I had no hair when Hattie was born and reassure each other that I’m better now. Harriet herself has a strong awareness, which seems something strangely instinctive about the significant part she played in our drama. in fact as I sat at the keyboard trying to write this the other day she came into the room and said, “Are you writing about when I was born and you were ill?” I reassured her – and will need to keep reassuring her – that I wasn’t ill because she was born.

I’d like to say that having cancer improved the parts of my personality that I’m not so keen on – my impatient, quick-tempered side. Or that it encouraged me to reach for my dreams, because life’s too short to waste, and other such cliches. in reality, I’m still impatient with the kids. More than I should be. I’m still a worrier about things that I should have learned to recognise as unimportant, but these days I do try to remind myself, when work gets too stressful, that I faced more than this, and was lucky enough to come through – so far.

Roger and my mum, and my brother and sister, are still enormously supportive, but I don’t always share my deepest fears now. The feeling of panic is not lessened by sharing – in fact, my concerns increase as I describe worrying symptoms or feelings. I know that my mum was deeply traumatised by my experience, and Roger had to love me through my worst times ever. I think that makes us close, but facing up to that fear also takes some of the magic out of things, for the time being anyway.

Having cancer has not changed me as a person, but I’m starting to pick up the pieces of my life again, daring to trust that I have a future once more. only now am I beginning to understand what I nearly lost. And it’s a lonely place to be. But tomorrow is another day, I’ve got to go to work and tonight I’ve got to mark some essays, do some ironing and make the kids’ packed lunches for school. It’s these small things in the present moment that drag me back from that lonely place. Being busy buries that kernel ever deeper. But I haven’t yet decided if that’s good or bad.

• Kate Purdy blogs at calamityandotherstuff.blogspot.com