See the funny side? Don't make me laugh

I am drying Betty after her bath with a giant cornflower-blue towel that exactly matches the colour of her eyes. She is giggling and twirling and wiggling, forcing me tiredly to reach and trap her and bind her over and over again in order to wipe away the remaining beads of water on her sturdy little body. I am so tired but this is the last job of the day and she is so lovely and so I hold my temper and keep going.

I let go of her to reach for her clean pyjamas on the radiator beside me, and she springs free, backing out of my reach with a mischievous twinkle. She bends, scoops the towel up and throws it over her head, then stands just apart from me, tottering under the heavy material, her laughter muffled, waiting to be claimed. I protest, and she peeks out from under it and beckons me in. I go closer and closer to her and she holds out the towel like an awning, a refuge, until I am under it with her, breathing in the heavy damp air that smells of her baby body and nose to nose with me she raises an eyebrow and I wait expectantly to hear what it is she wants and Betty asks me: "Want some cup of tea?" And the bubble of sour anxiety that I have carried inside me all day pops, just like that. I snort out a laugh and Betty joins in. We laugh and laugh and again I thank God most fervently for my baby, who makes me laugh and relax and forget for a while about my worries for my big girl.

When you have an autistic child everyone says you've got to laugh, or else you cry, but more often I cry.

Everyone says, you've got to have a sense of humour, but actually, increasingly, I don't.

Everyone says, come on, can't you take a joke, but these days, the answer is often no, I can't.

Most of the time I can pretend though, and most of the time I'm good at it. I have a perma-smile from years of practise and a whole range of artful poses: the smile and the nod; the half-chuckle; the sympathetic roll of the eyes; the "goodness, I know" moue of the mouth; the shrug that says "hey, what can you do?" I am diplomatic, and calm and I pour oil on troubled waters and I take deep breaths.

Sometimes I use these responses when other children bully my daughter and laugh at her and tell her their rudeness is her problem and I have to face their parents in the schoolyard. Sometimes I use them when the school phones me again to tell me of another incident and explains that Grace really must learn to react more calmly and that often what happens is her problem. Sometimes I use them when the local authority needs yet more paperwork and proofs and reports and appointments before they will help us and the problem of chivvying and collating and the burden of proof is my problem.

Today, I used them when a crap, so-called comedian made a crap joke about Asperger's on Twitter and then told me to fuck off when I objected. Tonight, I am using them as a television channel airs a programme about a person with Asperger's struggling to find love and calls it "The Undateables" and effectively tells me and all the other parents who fear daily for our childrens' fragile psyches to fuck off, if we object to the name of the programme, it's our problem.

Most of the time I use these responses because not to do this, to breathe calmly and shrug and smile, would make daily interactions virtually impossible. I do this because I have to keep going and I have to make people like me in order to get good results for my daughter. I do this because I refuse to allow myself to be infected by the small-minded meanness, ignorance and crassness that so often comes our way.

But inside, often, I am boiling.

Inside, it is very not alright, fuck you very much.

Inside, I am banking the anger and pressing it down until it is small and hard and hotter and more powerful and it provides me with fuel and drives me to make things better.

And then I will have the last laugh.

Grace Under Pressure: going the distance as an Asperger's Mum, will be published by Piatkus Books in October