I agree that you need to find out your actual tongue weight it should be 12% of your loaded ready to travel weight. So approx. 5500lbs would be approx. 700lbs. Once you know where your tongue weight is at then you can setup the WD hitch for the loaded trailer.
It takes time and patience. Once it is dialed in you will notice a big difference. After you get it right, i might suggest ditching the friction sway bar and going to a Dual Cam sway control setup. It wod be much better for your truck and trailer.
Good luck!