I have a story to tell you, but I’m afraid I’m a less than perfect narrator because there are crevasses in my mind that I fall through whenever I try to tell it.

I can pin my finger firmly on the moment I began to wonder whether something was really wrong. From behind me, I heard a child’s voice, small but determined. I contorted this way and that in search of its pestering, persistent owner, but I was alone.

This was new. Later that evening, I watched a psychedelic display of electric lions, roaring tigers and the cast of the film Jumanji cavort on the bare blue wall. I wasn’t afraid, just captivated.

Yet a voice, this time my own, questioned how I could be seeing such a spectacle and suggested, gently, that perhaps those around me were right – things were very wrong.

Given that all of this was happening in my room in a psychiatric ward, I was a little late to the realisation party. There had been other not-so-subtle hints – in my belief that my baby had been swapped at birth, for instance, and that road signs were tailored messages for me.

I held these truths to be self-evident and never considered them to be odd, let alone symptoms of an illness.

Yet that’s precisely what they were – evidence of a sick and struggling brain. I was diagnosed with postpartum psychosis, a severe mental illness that affects about one or two in every 1000 women soon after childbirth. It can cause a litany of symptoms, from anxiety and profound sadness to chattiness and euphoria.

Women with postpartum psychosis can rapidly cycle between moods and may experience hallucinations and delusions. Although it’s more common in women who have bipolar disorder, it can affect women who’ve never had mental health issues. It’s a psychiatric emergency that requires urgent treatment because the symptoms can start suddenly and get worse quickly.

At its most severe, it poses a risk of suicide. It can even lead to accidental harm to the baby or infanticide, though this is exceedingly rare.

Unfortunately, infanticide grabs headlines and so women who suffer postpartum psychosis often worry about the stigma of the disease.

Many don’t seek help. One Australian study found that, of those women who had symptoms of postpartum depression, 41% had not sought help within nine months of giving birth. Often, women said they believed their symptoms were normal and would go away.

I can identify. I feel the fear of stigma keenly as I write this, afraid of how you’ll judge me as a mother and as a person. And for months, I too thought my symptoms were a normal part of motherhood and would resolve themselves. This was made easier to believe because the symptoms of postpartum psychosis can wax and wane.

Yet at the peak of my disease a nurse told me I was one of the sickest women she’d seen enter the ward. This shocked me. Sure, I was a bit anxious, a bit bothered, but surely not seriously ill.

Being a parent is meant to be hard, isn’t it? Yes, but it shouldn’t involve thinking trees are angry with you.

It seems obvious now, but thanks to the disease I lacked what’s called “insight” in psychiatric parlance – awareness of how ill I was. Now I know how serious an illness I had and how lucky I was to eventually get specialist medical help.

One in five mothers suffers from depression, anxiety or psychosis during pregnancy or the first year after giving birth, according to a 2016 report by the independent Mental Health Taskforce for Britain’s National Health Service. Many people who tell their stories of severe mental illness do so from a safe distance of years. My story is only months old.

It was my first pregnancy and it had gone well, but as the end was in sight, it emerged that my baby was destined to be a contrary madam. Beatrix was eventually born by emergency Caesarean section in January 2016. Now, as I reflect on the gap between my expectations of bringing her into the world and the reality of it, I see a dark, vast cavern.

I had expected to be the first person to hold her. I’d imagined a celebratory moment as the three of us were together as a family for the first time. In fact, because of the cocktail of drugs I had been given, I spent most of my C-section trying to throw up. My husband was therefore the first to hold her, and clutched her in one arm and a sick bowl for me in the other.

I also bled quite a lot, and when the operation was over I began to shake violently, so I still couldn’t hold her. We returned to the maternity ward, where a nurse tried to get Beatrix to breastfeed, but I was still shaking too much. Ever resourceful, she hand-milked me and collected the milk.

And that’s not the least dignified experience I’ve had since joining the ranks of motherhood.