Maybe more time in the drivers seat may help.
I agree with Behindbars.
I did go with the "cheap fix". I have done coast to coast twice with no mods. You may be overcorrecting in response to a "draft" problem that is inhrent to all class A's depending on weight and size. The f53 chassis is not the best handling but works reasonably well. Check your tire inflation. Makes a big difference. Increased rear stabalization using stabalizer bars or stiffer springs can help along with anti sway will relieve much of the driving fatigue. I have no real compaints after 24000 miles. My frustration is buffeting in high winds or gusty conditions in which case i slow down. I believe front steering stabilizer would help to some extent. For me, noise cancelling earbuds makes driving more enjoyeable while driving. There is no magic bullet.