have a safe trip.... you can get a instant heating pad.. to put on the back of your neck.. also a small footstool helps to put your feet up,.... a neck pillow againt your neck will help , esp. with the heat...
make a few stops and when you get out of the do it soooo slowly,,, takes ya 5 mins just got stand straight, then strech your arms and legs and walk a bit,,, get ready for the next miles ahead...

TAMMY
i travel over 8 hours,,, in one trip... this helped me