When I was home from Pakistan and we did our trip to S. Texas I got something similar on the second leg of the trip from Austin to Houston. The little bolt you see on yours kept loosening up on mine no matter how much I tightened it (didn't have a torque wrench with me on the road). I ended up using some blue Loctite on it but it still loosened up as the trip went on. I also discovered how much the washers made a difference. I am still baffled how a 1/8" piece of metal can make such a huge change.
There is a post further up about not having enough truck to tow your trailer. I am towing a slightly smaller TT with a similar truck and had no power, stopping, or any other issues after I got the hitch adjusted as best as I could. I still have a long way to go on figuring it out and getting it completely right though. I was apprehensive before pulling our TT with our Half ton truck but the only thing that really bothered me was the fuel mileage of a bit over 8mpg. Not bad considering my 2011 2500 only would do 10-11mpg by itself with no load (diesel).
How I left from picking it up form getting repaired. First trip with truck and setting up hitch.
After asking for some advice here and making some adjustments. Still not correct and even thought the picture does not reflect it the front is at normal height and the rear is the same height as front with was roughly 1.5-2.25" from normal ride.