If you ever experience sway grab a handful of trailer only brakes. It will straighten things out. Otherwise the ocillations will get more violent until the entire rig is uncontrollable. For your set-up with a 35 foot trailer I would opt for a better hitch, a Hensley, ProPride or PullRite. These three control sway, not just mitigate it. You have a friction based hitch, the three mentioned do not use friction to control sway. Weigh your tongue and make sure you are at or around 13 percent of the total trailer's weight on the tongue. That will also help eliminate the possibility of a sway episode. You have a lot invested in your truck and trailer, why not connect them with a better hitch? If a non friction based better hitch saves your bacon only once, it will pay for itself many times over.