The lacrosse ball is helping. Yes, it's not a magic bullet, but it is helping loosen up my back, butt and hamstring muscles. Today's squats felt better already. Yes, I'm working on form as well, since that is what put me in this position to begin with. Call me a sucker, but placebo or not, I feel it helps. We'll see about this as I up the weight though.
Could be quadratus lumborum.
Hip bridges might help.
No.