I’m not sure what you’ve tried but I’d start with putting blocks under your jacks so they don’t extend too far out. Typically, the less your jacks extend the less movement you feel in the trailer.
I know what you’re going through! The Morryde Hitch stabilizer, along with blocks under the jacks like Tory said above has worked wonders for our trailer. No noticeable movement that I can tell.
We have a fifth wheel and always setup a tripod stabilizer in the front and stabilizer in the rear, which seems to alleviate any rocking. I know you said you had a TT so maybe there are similar options for that.