Questions with sway and hitch after Driving on Highway

I think you need to find and fix the sway problem first. The sway control on the hitch is there in case a problem comes up to cause sway, not to help control sway problems that are there now. Usually sway is caused from too little tongue weight. Do you have extra weight on or near the rear of your unit. If you have ST tires, you are flirting with problems if you are towing at or above 65mph for any length of time.