As my husband and I approach the UCH Macmillan Centre for the results of the biopsy for a lump in my neck, I wonder if I’ll have a single malt at the pub afterwards, or a warming whisky mac. Richard, usually a decorous drinker, has suggested the stiff drink before we head home for the Secret Santa party we’re hosting later on. The sooner we get this appointment out of the way, the better.

We take our seats in the reception area. When I was here two weeks ago, I watched as a Macmillan nurse approached a seated couple and chatted. Clearly one of them had cancer. I don’t want anything to do with Macmillan nurses.

When the receptionist calls my name, I tell Richard to stay behind, to increase my chances of not needing him. “If anyone comes to get you,” I say, “you’ll know it’s bad news.”

The door to the consultant’s room is open. He is not alone. He was the last time I saw him. This time there is a doctor behind his chair, someone by the window, and a Macmillan nurse.

“How are you today, Genevieve?” The consultant, dishy, good cheekbones, dark hair, pulls his chair closer to mine.

“I’m fine.”

He leans in closer.

“How are you in yourself today?”

In myself.

Catatonic with sudden dread.

“I’m fine, absolutely fine.”

“There is only one way to tell you this. The tumour is malignant.”

“Can someone get my husband please?”

I wasn’t exactly expecting the cancer. I’ve simply lived in its shadow. My own mother died from cancer, liver or breast, I’m still not sure which, when I was nine, four years after my American father died. Now history is threatening to repeat itself, leaving my sons, aged 14 and 12, motherless. I’ve often imagined the dread scenario and its effects on the boys, but I never foresaw how my own cancer would prod an old wound: the shame of being parentless, and how illness would rub revulsion into the wound: revulsion at finding myself first vulnerable, weak and, worst of all, diminished. Illness doesn’t go with the orphan’s way of doing things, which is to look after yourself, live on your mettle. Getting sick begs a buried question: who is going to look after you? But I only find that out during my recovery.

Being an orphan is shameful partly because you are different, and no child likes that, and because parents and family confer status and safety. Not having parents is like being on the run. You’re an outsider. You do things your way, because there is no other way. Think of the literary orphan Jane Eyre. Proud, fiery and shamed by her lowly status, she secures herself a governess job. Had Charlotte Brontë lived later, she might have had her heroine advertise her services in The Lady, the weekly magazine that has provided posts for household staff since 1885. In 1972, after my own guardian was unable to look after my brother, sister and me, a classified advertisement was placed in it for someone to care for us. “Three recently orphaned children,” ran the ad, “need kind, loving, cheerful and intelligent lady (can be single, divorced or widowed) or married couple in 30-50 age group to make a home for them. All three bright and very rewarding. Boy (15), shy, articulate, bookish, girls (10 and 9), musical, interested in horses, gardening, sophisticated for age. All at Sussex boarding schools.”

There were 50 or so replies. A 50-year-old from Dorset is “very lonely and want[s] more than anything to be needed”. A divorcee with no home for her children wonders if it might be possible to “merge my needs with the obvious great need of the three children?” An animal-loving, cultured couple sound OK. She recently starred in a Truffaut film and he once ran the Human Rights Society. “We have many interests,” writes the woman, “and I have had experience with old ladies, mental patients, cripples, the blind, and prisoners.” Orphans would have rounded off her list quite nicely.

In the end, we lived for three years with a single woman called Tamsin, a friend of my guardian’s mother. Like The Lady applicants, her do-gooder impulses mixed with her dependence offended my pride. I wanted to deserve better. Before us, she had once been a paid companion to a lady travelling in Europe. Being paid to bestow friendship struck me as pitiful; but let’s face it, so was being paid to live with orphans. When I was 13, she walked out during the summer term after three scratchy, loveless years. My brother, then 18, was summoned back from a summer job in New York to look after me and my sister that holiday. This was the summer of our disgrace, and we spent it being grown-ups. Tamsin had taken most of the furniture, and we negotiated the blankness and the abandonment. One day my sister and I made a shepherd’s pie. When I served it up, the flesh was pink. We hadn’t cooked the meat first.

I feared getting cancer because I didn’t want my sons going through what I went through. After the diagnosis, my immediate concern, apart from surviving, was how I would continue to protect and care for them. Even as the chemotherapy and radiotherapy took their toll, I tried to hide my vulnerability from them. One day, the youngest, Sebastian, came into the room where I was on the floor, surrounded by medical milkshakes, syringe, and other paraphernalia. I was giving myself a “feed” through my stomach tube. I quickly covered everything up.

“You don’t need to be ashamed,” he said. He was right, but it felt so hopeless being ill, pathetic really. Not only did I feel like an orphan for the first time in years. I was a sick orphan.

Two months after my radiotherapy finished, I hit rock bottom, physically and mentally, thanks to a low intake of calories, a high one of morphine, and a battered immune system. I felt diminished. My now acute shame at being helpless and ill took me back to the summer of our disgrace, only now my shame held a mother’s anguish. The boys depended on me, yet there I was, ineffective. I lost any sense of connection. The sun shone. Let it shine. The boys came in and out. Whatever. Then one day I thought: perhaps, when you are very ill, you want to be held, as you’d hold your own children. What, I asked myself, would it be like to be looked after by a mother – a preposterous, childish thought for an adult. But the thought, emboldened, repeated itself until suddenly I said: “I want my mother.” I didn’t say the words. I howled them. Appalled, I sipped some water, pretended it never happened.

Three years on, having glimpsed what others expect from a mother, I am alert to the love my boys take for granted, and luxuriate in the prosaic power of motherhood. It’s the every day stuff that builds security: being present, asking questions, listening, cooking for them, sparring with them verbally. I revel in all this now.

As a child I used to listen out for my mother’s voice. Being ill made me do so all over again, and my longing for it has changed how I speak to the boys today. I am still shouty, when I am cross. But my voice has softened, embodying a more loved, more loving internal one: less shameful orphan, more a humdrum, warts and all middle-aged mother, one whose cancer might return. And might not.

Either way, the boys are insured against loss, and so am I. History can never repeat itself.

Milkshakes and Morphine: A Memoir of Love and Loss is published by Square Peg on 25 January at £14.99. To order a copy for £12.74, go to guardianbookshop.com