APT wrote:
Start with those free changes, lower ball height, restore all weight (or estimated by body height) front axle weight, increase tire air pressure when towing. I suspect you'll see improvements.
X2, and inflating the tires to the max 44 psi will make a big difference as well as getting the nose on trailer down and getting your hitch dialed in. You can always add the second friction sway control if you want.
As to going with the Equalizer Brand Hitch, that's what I run now and it is an improvement over the type you have, but I can still feel the big rigs go by.