Say it ain't so....it's a 3/4 ton it can't have sway issues...lol sorry had to just take a jab at the you can't tow anything unless it's a 1 ton dually crew that's on here....
In all seriousness like said above check your tongue weight loaded with your toys in the back. Take it to the cat scale. A lot of times these toy haulers are tongue heavy empty to compensate for adding weight in the back but some not enough or you just may have to arrange things differently inside. It sounds to me you are under the minimum 10% required tongue weight giving you that sway effect. Also have you messed with the WDH settings at all? A WDH set incorrectly can ruin anyone's towing experience.