My recommendations as a nearly lifelong carsickness person is #1) wearing sunglasses if you don't already, #2) don't use your phone at all or try to to read #3) maybe try dramamine but start with like the teeniest doses possible (I'm talking like, a chip off a pill) and work your way up, cuz I've found even the non-drowsy kind can build up in my system after a few hours and make me dizzy/extremely tired.
Drinking water might also help if the headache is forming from dehydration (also if you drink caffeine, try to make the cut-off point for that about 2 PM, your body will thank you). I realize following through on all of these is unlikely, but I hope at least one thing helps you (hang in there)
My recommendations as a nearly lifelong carsickness person is #1) wearing sunglasses if you don't already, #2) don't use your phone at all or try to to read #3) maybe try dramamine but start with like the teeniest doses possible (I'm talking like, a chip off a pill) and work your way up, cuz I've found even the non-drowsy kind can build up in my system after a few hours and make me dizzy/extremely tired.
Drinking water might also help if the headache is forming from dehydration (also if you drink caffeine, try to make the cut-off point for that about 2 PM, your body will thank you). I realize following through on all of these is unlikely, but I hope at least one thing helps you (hang in there)