As weeks go, the past couple haven't been that bad.

I recently took charge of another child (for complicated reasons I won't go into): my niece, who now lives with us. My elder son Julian had a three-day staycation in KK Women's and Children's Hospital for a suspected case of appendicitis (it wasn't). There were the mid-term exams to mug for - revisions to supervise; tuition classes to chauffeur little people to. And yes, that nasty flu bug going around finally caught me, even though I tried my best not to go anywhere or see anyone.

But other people have worse days and worse things to grapple with. At least, between the two of us, the Supportive Spouse - who is much more capable than me - and I had the crises licked. Forts were held. Defences manned and womanned.

Even so, I could feel it coming on. The crashing sensation when the adrenaline wears off, now that disaster has been averted, and all the wind suddenly goes out of your sails and you're left a crumpled heap on the unmade sheets. You look sh** and smell a bit (to quote my favourite retro-emo band, The 1975).

This morning, I woke up, dragged myself to the car, made the hour-long school run and then collapsed back in bed, looking like something the neighbourhood tabby had chewed up and spat out.

The money- and/or time-saving scissor-job I did on my own hair didn't help. Aiming for rock chick, with feathered asymmetrical forelocks, I succeeded in achieving only "mad person".

So here's an honest fact that few parenting columnists might want to admit: I'm as bad at this as the next girl/guy. Parenting is some kind of extreme endurance job, with no option for timeouts or sick leave. Some days, I just want to sit in the naughty corner and cry.

I remember the first time it happened. It was 2010. My younger son Lucien was barely six months old and I still leaked milk whenever I felt melancholic. Maybe it was late-late-onset post-natal depression, even though we'd made sure we had ample help - a confinement nanny in the first month and then a domestic helper who was great with the baby.

Whatever the case, I simply broke down. I was incapable of even driving Julian, then four years old, to his kindergarten a few streets away. All I wanted to do was stay in bed and watch Revolutionary Road (2008), with Kate Winslet and Leonardo DiCaprio playing out the unhappy-ever-after version of their Titanic pairing, and weep my eyes out.

Things eventually got better, with a lot of patience and care from the Supportive Spouse. But I also knew that something had changed; an illusion had been punctured.

One day, while singing karaoke at home, I was belting out Fergie's Big Girls Don't Cry, when Julian piped up: "But that's not true, isn't it? Big girls DO cry." And then he gave me a meaningful look.

It felt horrible, the knowledge that in breaking down, I had also revealed to my son the possibility of my fallibility. How could I expect him to trust me to take care of him, when I had demonstrated so clearly that sometimes I could barely even take care of myself?

But, maybe, it's better to quit maintaining the false image of parents as gods you cannot contradict early on.

Over the years, it would happen again - and again. Some days, getting out of bed was a challenge. Then the spell would break and I would be back to normal, tackling the mounds of overflowing laundry and hustling the kids out for impromptu picnics.

Trying to break the cycle, I tried counselling, took better care of my emotional and physical health and came to terms with the fact that this was the way I was built, motherhood or no.

Last month, my dear aunt - my mother's sister, who was also married to my father's brother, making her both ah yi (in my maternal Teochew) and ah sum (in my paternal Cantonese) - died after a battle with stomach cancer. Entertaining my little nieces, her granddaughters, at her funeral, I was struck by the thought that, with my aunt gone and other relatives from her generation getting on in years, my cousins and I are now the adults who have to step up when the family needs us.

The thought filled me with a nameless terror. That night, I had a horrible dream in which all my teeth fell out. I'm not ready for this. I'm not ready to be permanently adulting. How is it that I happen to be running a household?

So here I am, typing this while listening to melancholic emo-teen band music that would surely have my firstborn tutting in disapproval.

It's my self-appointed day off from adulting, when I can watch all the Misfits (2009-2013) science-fiction TV episodes I want.

When the main character, Nathan, shouts from the rooftop what a bunch of screw-ups they are, messing up bigger and more beautifully than any generation that came before, I want to stand up and clap. And then I find the strength to carry on with my day and the chores.

If I could turn back time and travel back to when I was pregnant for the first time, here's what I'd tell myself: It's okay to stuff up. It's okay to have a meltdown. There's no such thing as a perfect mother. Not even such a thing as a moderately successful mother who is calm and right all the time (shut up, if you're one). The important thing is to recover and move on.

It's better for everyone to acknowledge that mummy meltdowns happen and disabuse the young women out there of the pretty parenthood picture. Because when you realise that it's hard for everyone, in all sorts of ways to Sunday, you can get over the carefully curated children- complete-me campaign and just get down to brass tacks.

Having a bad parenting day? Trying to suck it up and hold it all in? Don't. Allow yourself to go to pieces, just for a while. Feel better? You should, because you're probably doing better than at least one person - me. And with a better haircut.

• Clara Chow is the author of Dream Storeys (Ethos) and co-editor of WeAreAWebsite.com