Don't believe the combined weight ratings

Its easy to simply say the op's setup is wrong, and leave it at that. I've been towing since '85. My truck was level with the trailer. I believe there is one thing nobody here considered. As mentioned, my truck is a regular cab. The short wheel base, I believe had something to do with the poor handling of the 29 ft TT. As a 4x4, it sits high. I tested the handling of the (reg cab) truck on an open road by zig sagging and found it to be unstable as a solo vehicle. The truck was recently checked out and nothing was amiss. The short wheel base and high center of gravity had everything to do with how it handled the trailer. Short of a Hensely hitch, I don't see how a conventional hitch, WD and sway control could have fixed that. The Ram, as per Dodge specs, has a Tow Rating, (not combined rating) of 9,000 lbs. A four door may have made the difference.
(Sorry, I should have written, Tow rating not Combined)