So glad you found a solution. The hitch you picked is pricey, but compared to the camper and truck, not such a big deal with all the benefit you get from it. Camping is no fun if you hate driving to get there. Plus the safety is hard to put a price on. In your case you were not correcting for an overloaded truck, just a combo that didn't want to work well.
In my opinion, the Blue Ox doesn't really have much in its design that will radically improve sway. I have not experience with it but I am an engineer with a lot of experience with a lot of things and a lot of experience towing. I've used no sway control, a simple friction bar, and the Reese Dual Cam. I've been using the Dual Cam for 11+ years now and I love it. I think the brackets that connect to the trailer and not designed well and often need additional help in staying in place. But the sway control they provide is considerable. The simple friction bar to me helped a lot if tightened enough, but it also tended to hold the trailer and TV in a non-straight line. Where ever it stopped in its movement, it just wanted to stay there. It was hard to drive straight. The Dual Cam is always happy to drive straight ahead and provide even greater sway control than a friction bar. The cams want to stay in the straight ahead position on the Dual Cam. Mine is quite although on my current trailer (1200-1300 lbs TW) I do need to use a little Vaseline on the cams. I never had to on my prior trailer with 850 lbs of TW. Both of my trailers have tended to run 15% + TW. No issues. The other thing that makes a huge difference is tire construction. Depending on the vehicle tire size/type that may mean a switch to a higher performance tire that also has a higher speed rating. Or typically on a truck that means switching to a load range E LT tire.
The Hensley or Propride are a hitch category of their own and seem to be well worth it if you have the money to spare. Glad you are happy with your solution! Happy camping!!