billy
Before throwing in the towel, is your truck a 4x4? They're substantially stiffer than 2 wd imo.
I'd guess most of the jarring is coming from the front which has virtually no additional weight compared to empty maybe even a shade less. First I'd make sure you don't have the front tires too stiff. You may not need the full 80 psi up front if that's what you're running.
Same goes for the rear tires, but 3700lbs should smooth out a dually pretty nicely. Correct air and little to no airbag pressure if you're pumping up the bags too. Let the truck squat a little, keep it on the springs.
If you can determine its from up front, places like carli and Thuren make softer front coils. Not ideal imo for sway with the camper but those softer multi rate springs maybe with an upgraded from sway bar will be about the best you can do up front.
Hope this helps give you some ideas.