It is referred to as white knuckle syndrome, I got rid of it years ago by installing a Hensley hitch, no suction and no sway either, expensive at the time but looking back its on its fourth trailer and I can drive relaxed with one hand on the wheel (if I want to) so it was worth every penny.
"Well that didn't go as expected"
2015 Chev 2500HD Highcountry Duramax
Cedar Creek Silverback 33IK
Donald&Casey cairn terrier
Rest in Peace Mary my darling wife.
Scottish by birth Canadian by time.