I used to tow my 32' 7000# travel trailer with a 1/2 ton. I know what you are talking about. The big trucks would suck me over, then spit me out. I had a Reese WD hitch with a friction sway control.
Then I upgraded the hitch to a Reese Dual Cam (now called
Strait Line - see here) and that made a BIG difference. Driving was much easier when then big trucks passed. The curved end of the spring bar is held up by a cam, which is supported by an arm and chain. It helps keep the truck and trailer in a straight line until you start a turn.
Then I bought a 2500 truck. Even better yet. It is rare that a semi moves me around. Much less tiring.
If you want to keep the 150, upgrade the hitch. It really will be much better if you upgrade the hitch and the truck.
Been there, done that.