Can anyone help?

I'm on a deep reach forklift for 10 hours a day. You know, the ones with a deadman switch. I switch between 3 pairs of workboots on the weekly because my feet are killing me after 8 hours, and after 10, they are trashed!! I have gel inserts in each pair, but it seems as if nothing will help them. My heels and the pads under my toes, seems to be the most areas affected.Any advice is greatly appreciated. What do you guys do to keep your feet from hurting you so much???