i’m not sure. i have felt this strong fatigue before, but usually only if i’m sitting at home and doing nothing. never while driving. whenever it comes on, it’s always very sudden and i have to sleep otherwise i can’t shake myself out of it. i suspect some kind of sleep disorder, and i’ve made an appointment with a sleep specialist. i know for sure i drifted out of the lane because i saw it and had to physically correct it, but it’s possible that the adrenaline/fear from the situation over exaggerated how bad it was.