Starting school can be a traumatic experience – for the parents

There is so much to worry about, said Gertrude Stein, you might as well not worry about any of it. But then again she never dropped two children off at school for the first time. Mine started last week and while one was fine, the other stood in the doorway of her new classroom looking tiny and lost and very alarmed and did the thing that, in extremis, parents fear more than tears: no tears. Looking on from the corridor, I felt something lift up and leave my body like the spirits in Ghost.

Related: I’m a paranoid parent – and proud of it | Catherine Shoard

Controlling anxiety is the great labour of our age and one with no discernible end. I try to divide my fears into categories: those with controllable outcomes (there is a mouse in our skirting board), those with no solution but that I consider manageable (why do I persist in buying jeans that are too small when I know I’m too lazy to return them?), and those that form part of a great, amorphous cloud of dread that hovers just over the horizon (where will it end? Why do we live like this? If there is a God, why did He allow Instagram to happen?).

When my children were babies, the existential terror of being responsible for other people was so vast the only way to control it was to attach it to real-world anxieties. It didn’t matter how fantastical; I just needed a shape to hang on to. For a long time, every time I passed the waste-disposal chute in our hallway, I had to staunch a mental image of tripping, wrenching the door open and accidentally dropping one of my children down the 13-storey shaft to the cruncher below. It wasn’t great, but it was better than shapeless fear.

That phase eventually wore off to be replaced with a worse one: the fear not of freak accident or ill-health but unhappiness. Were they unhappy? Why were they unhappy? Was it contextual or constitutional? Were signs of distress actually a good thing, given that the unhappiest people in the world are the ones who can’t show their unhappiness?

Once my children learned to speak, it was curious to observe that their own anxieties trammelled along similar lines, the necessity of attaching a cause – any cause – to their fears. Over the past few months, I have talked them down about getting struck by lightning, getting killed in a flood, having a creature “come out of the wall” at them – and something I still can’t get a handle on about the Spice Girls not being real. “What if a bug crawls into my mouth?” asked my daughter the other day, and my answer – “It just wouldn’t, don’t worry about it” – was clearly inadequate because it keeps coming up.

Meanwhile, with school, my own anxiety seems to have gone back to square one: amorphous dread. The place is good, and safe, and well organised. Apart from the agony of drop-off, my girls seem happy. But handing them over has thrown up the dust from those earliest days of unsoothable panic and here I am once again: wandering the aisles of the supermarket on a Tuesday morning, crushing an indent into the side of a pack of tofu sausages while shouting at myself in my head. Get a grip, woman! What would Gertrude Stein say?!

• Emma Brockes is a Guardian columnist