Not tonight, I have a headache

Today was a migraine day. I’ve had them all my life and yet the pain remains shocking, every time. Shocking how impossible it is to do anything else, terrifying how easily my whole consciousness closes down to a bright white thumbprint of pain. 
I have a friend who’s only ever had one migraine in her life, when she was in her mid-20s. She went A&E, convinced that if she wasn’t having a stroke anything this painful must mean she had some hideous infection past the blood-brain barrier at the very least.
That’s what’s so horrifying too, the pointlessness. At least if you slam your finger in the car door, you can see that damage has been done, that it’s good to get constant messages to keep the digit still. If you’ve got flu, those aches keep you lying in bed where you can heal. A migraine means nothing. I had them when I was two years old. They meant nothing then either. Just simple suffering, caused by no injury or infection, leaving no mark when they’re gone. 
The invisibility is also problematic. When I cancel meetings because I have a migraine, I always imagine that the other person might think I’m lying. It’s the kind of thing you can say, isn’t it? How can anyone check? I was disbelieved a lot as a child with migraine. There’s nothing to show. It’s the kind of lie a child might tell. 
A kind commenter sent me a message suggesting a diet free from foods containing ‘histamine’ might help. It was thoughtful of her, but I’ve already tried every exclusion diet possible. When I was a child my mother thought I might be allergic; for years we carefully noted down what I ate every day, trying to establish a pattern, weeded out likely contenders. It was comforting to think I might have some control, but it didn’t really help. As an adult I’ve eaten all those foods and never got a migraine from them. Sometimes I know the cause: I didn’t sleep well, I haven’t been exercising enough, I got dehydrated, I was overstressed. And sometimes I just never know. It’s like my migraine is a demon, clamped to the back of my neck, waiting to stretch out its long finger and erase a day or two as if they were nothing at all. 
Why am I writing this? Not to elicit sympathy really – these are my migraines, other people have their issues too, many more grievous than mine. I’m writing this out of pure superstition. This was my second migraine in four days. The first one erased Friday afternoon and evening, sending me whimpering to bed at 8pm, waking me up nauseous at midnight. I had a conversation with my migraine today, which is the kind of thing you do when you’re in a lot of pain. I said “if I write about you, will you go away?” Half an hour later it was gone. So this is the fulfilment of a promise to the Demon Migraine. Go away, stay away, please no more.