If the tires are rated ST, slow down. They are normally rated to run less than 65 MPH, and even slower is better. The next thing is putting better tires on, and unless you have 16 inch wheels, your tire options are somewhat limited. Goodyear came out recently with a USA made trailer tire that is supposed to be much better than what was available, called the Endurance. Might be worth looking at.
https://simpletire.com/goodyear-205-...5N%20724864519
With 16 inch wheels, there is also the Goodyear G614 and the Sailun S637, which are both 14 ply rated all steel trailer tires. There are other options for all sizes, it just takes research before you buy.