So this is what I came up with last night. Not sure if I like it. I made it by cutting and shaping a piece of 1" x 1/4" steel, originally from a huge 8" x 8" angle bracket. I was trying to get the hitch lower to level out the trailer, but at this length I'm concerned with the weight of the trailer pulling on the steel bar and rotating the bar backwards, which could wreck the frame somewhat.

The other reason for it being so long is that I used two holes that were already in the bracket. I'm not sure if the drill bits I have could handle drilling through 1/4" steel if I wanted to make a new hole farther up.