Questions with sway and hitch after Driving on Highway

All I can think of is
1. Not enough tongue weight
2. I have an equal-I-zer and to my knowledge you DON'T want to grease the friction points. I grease mine at the swivel points where the socket that holds the bars swings back and forth, or in and out for turns, (hope that makes sense). This keeps it quiet and allows the friction to do what's its supposed to do.

Came through some pretty stiff side winds on the freeway last trip in my 1/2 ton Ford and had no problems. Good luck.