I have had chronic headaches for 17 years. In that 17 years, I've maybe had a month of days without a headache. So, 3 years ago, I was put on a med to help me to not have them. After rounds of tests, and finding no reason, yes, I've had my head examined :-). The med never got rid of them, and I've quit it cold turkey several times, spinning me into a dark abyss. So I would go back on it.
I am in the process of weaning off of the med, now, slowly. And there is a view of the dark abyss, but I am staying out of there, moving slowly around the edge of it to pass it.
So... if I seem a little 'off' or maybe short, or cranky, that is why. I'm fighting a battle. But I'm doing it the smart way and I'll move past it. And soon, the real me will be back.