Well nothing is going to help out in the desert when you have high winds, you know those areas where they warn the trucks they could blow over. Slow down or don't travel during high winds.
The tag axel is usually a fairly stable setup. Check your shocks check your suspension bushings for play. Air pressure in your tiers. You could add air bags to the front to help. larger sway bar and a panhard bar to locate the rear axel. But really not enough info to be definitive. Make shore your tag axels are working properly.
Bill