Ahh, thats some road kill level stuff
Stop every 5 miles to fix what you just fixed before you then have to fix it again.
Yup, had the same thing happen to me one time. I had taken the tank out and cleaned it when I got the Jeep back on the road. I had just lead a group through a trail. We said our good-byes about 15 miles from the nearest town. I though I would go and check out a nearby dam before heading home. I made it down into the canyon, but coming out I barely made it. I had thought to put a filter before the pump when I cleaned the tank and it looked fine. Suspected the pump. Once I got on level ground it seemed OK for a few miles and then it slowly began to loose power. By time I got home I could barley do 15 mph.
Changed out the pump the next day, still had the same problem. Looked at the filter again and it still looked fine. I went ahead and took it off and pounded it on the ground a few times and sure enough some really fine clear like sediment fell out of the media. Replaced the filter and ran fine after that. I did have to replace the filter a few months later, had the same problem. They might run fine on the smooth stuff, but once the gas starts really sloshing around it can break up that sediment and send it down the line.