Maddy Costa's touching and personal response to Oxbow Lakes

I went to see Dirty Market's Oxbow Lakes hoping it would fix me. There was a pertinence to its marketing – “Oxbow Lakes dramatises a child's experience of his parents' conflicted feelings towards him and themselves,” no less – that made me think this play would KNOW. That it was coming from a place of knowing, because Dirty Market's directors, Georgina Sowerby and Jon Lee, are a couple, and have children. In the event, the play felt like the string and sticky tape, tomato soup and chewing gum that prove so ineffective in healing shells, because I saw it when so broken by a trip to London Zoo – can I just pause here for a diatribe against London Zoo? What a fucking nightmare of capitalist extortion. As soon as you walk in – and even getting through the gates costs enough to fill a fridge and food cupboard – it's trying to prise money from you. Take the kids to the toilet and there's the shop, taunting them. Just past the entrance are face-painting and a bouncy castle and fairground rides, all at extra cost. And then everywhere you go there are merchandise stalls, so there's no escape from objects of obscure desire that attract your children ineluctably, far more than the animals, most of whom are asleep anyway. I HATE IT. And the most recent visit was so traumatic that a) I never want to go back, not even to see again how beautiful giraffes' eyelashes are and how much otters love to lick each other's genitals, and b) I arrived at Oxbow Lakes drowning in my unfitness as a mother.

Oxbow Lakes starts with a party, an attempt at a party, poisoned by the child refusing to fall asleep for fear of the shadowy figures lurking in the dark, and the husband and wife (played by Jon and Georgina) arguing over their responsibility in voices choked by the frustration that cloaks guilt: the guilt of regret, of longing, of feeling inadequate to the task of raising another human. The guilt of knowing that a child is supposed to expand your horizons and perspective, yet feeling instead a narrowing of self and existence. How appropriate that this first scene plays out on an impossibly skinny rectangle of stage, the child a black shadow on a white curtain, casting a pall on everything the adults attempt to do.

But what starts as gruesome kitchen-sink realism (there's even a Look Back in Anger ironing board) transforms into grotesque fairy tale when we're moved behind the curtain to the kitsch horror landscape of Oxbow Lakes. The child has fallen into a bedtime story and disappeared into the night; his parents chase after him, mother frantic, Dad inept, both thwarted by a constabulary that would control them and creepy snobbish locals whose nefarious motives are obscure. There was menace here, but also comedy: characters styled as though in a John Waters film, all quiffs and kookiness, those played by Benedict Hopper in particular dry as dead leaves and daffy as panto. The deeper the parents sink into this murky, cartoon world – and again, the set is really considered, a series of painted flats in a magnified Victorian toy theatre – the more estranged they become, until one of them literally no longer recognises the other. Are they really searching for the child? Or a notion of happiness that might not even exist?

There was something problematic about the transition to the final space: a clumsiness in the handling of the audience, who were left behind then admonished for not following sooner; it slowed us down and interrupted the tension. The space we move into is the most menacing yet; I recall plastic sheeting, looming witches, lights swinging, a ribbon rope our only protection, a huge sheela-na-gig icon with gaping, lairy mouth – was it threatening to eat the parents? Destroy them at least. It is their last chance to recognise the distance between the real life they have come to think of as a nightmare, and this place of horror and fear; and because this is a kind fairy story, they do. They rediscover their love for each other, and for their child; they cry out, with relief, with hope, with expressions of love. My broken heart trembled, and longed to feel a similar redemption.

I don't know Georgina or Jon, but we twitter-spoke the next day, after which I sent Georgina an email, a tribute to her bravery I guess; I wanted to confess that I'd seen my darkest soul splayed across the piece, and ask if making it had helped her find a state of grace. She admitted in return that in some respects it worsened the strain, consuming both her and Jon through the summer, as they wrote and rehearsed and built the set and cleaned the venue, leaving scant space for their seething children (who, it transpires, are the same age as mine). For all that it felt like an ensemble work – particularly in the middle section, where a looseness in the text conveyed the multiple collaborative voices engaged in its creation – Oxbow Lakes felt acutely personal, too: a slightly jumbled, self-conscious, but willingly truthful portrait of the struggle to accept that parenting is a difficult, messy business, a concatenation of tiny defeats that puncture the spirits, intermingled with a joy so extreme it turns you to jelly. Strawberry jelly, that the kids consume whole. My life met theirs in that performance space; at points I'd glance around the younger people in the audience, wondering: do you have children? Do you want them? What does this story mean to you? Are you reading this as lived experience? As a cautionary tale?