The bolt he is referring to is the one under the hitch ball, that adjusts the angle of ball.
You know, just because a product advertises "sway control" does not mean all sway can be 100% eliminated under ever condition. Face it, a 35 foot trailer is a LOT of trailer and under windy conditions, it's going to push the tow vehicle around. Mine is also 35 feet, and that's a LOT of "sail" for the wind to catch and whip around. With enough wind, under the right conditions, even semi-trucks have blown over. You Tube is full of videos of trucks flipping over due to wind.
When you notice this condition happening in the future, you need to slow your speed down, and if that does not work, slow down more, and it that does not work, slow down more, and if that does not work ... pull over and STOP!
More than likely there is absolutely nothing wrong with your set-up, your rig, or anything else. You've just got to drive with common sense ... slow down or stop.