Glad you and your car are ok,,,
I used to routinely drive from Michigan to NJ, Michigan to Atlanta, Atlanta to Miami quite often...I finally decided that no matter what, I followed certain strategies to help me not getting sleepy,,,,
1. No big Calorie meals that sap your energy and make you wanna nap.
2. pack coffe in thermos.
3. crackers and cheese...keeps you busy snacking, and you digest the small snacks quite easily,,
4. I listen to talk radio when it gets tough,,music even when loud, can lull you further.
5. I slide the seat closer to the wheel, and keep the back fairly upright,,,,I know of cases of fighter pilots and tank drivers falling asleep on their inclined seats...
6. could be silly, but that is why I like the JVC head unit I have, because the bright colours help me rest the eyes once in awhile.