What Mitch said! If you fuel a "travel center" (used to be called Truck Stop) it'll have a CAT scale. I went inside first, but apparently all it takes is to pull up to the front axle line and push the button on the bottom side of a little raised canopy that's near your driver side door. Go inside and pay what in my case was $10. They'll give you a weight slip with three numbers on it: Steer, Drive, Trailer. For us: Front Axle, Rear Axle, Total Toad.
If it IS tire pressures or load distribution that you can do something about, we would like to help you NOW, so your experience is better for the rest of this trip.
I think truckers might say the conditions you described in your last post were knocking them around some, too. Gusty enough and you'll feel it in a Corvette.
You say you're towing. I'm not asking what the equipment brands are. I'm assuming you have a Coach-Mounted Towbar and a commercially-made baseplate. Also that all the bolts are tight, hitch pins all in place etc etc. What I'd like to know is: Are you using a Drop (or Lift) adapter between Coach and Towbar? If you are, and the wobble from Coach Frame to Towbar is even half an inch, the Toad can start trying to knock the Coach off track from behind. I didn't dream up or even ask for that observation. I was talking to Eric Davis of EricsRV in Sequim WA, another of the RV handling issues expert and he offered it. There are motion limiters from both BlueOx (which I prefer in this case) and RoadMaster that clamp down on the drawbar to lock the twist out of it.