Tongue Weight (getting sucked in by trucks)

All great advice! thanks! It is a smaller SUV, the wheel base is smaller, so that may be an issue. I also don't believe I've ever had the tires at max pressure, so that's another thing I will try...Usually with the WDH it is pretty level, It's just a white 'knuckler trying to keep it steady when being passed or passing large trucks. I wouldn't say "squirrly" per-say, just difficult to keep it straight. It doesn't sway too much, except when passing... as I do have a sway bar (but I set it rather loosely) I'm new to towing anything except a pop-up, and that towed effortlessly with our mini-van. That being said, any advice helps, and I won't take offense, because I don't have a clue :)

Thanks again!