24M Back pain making me stiff and move weird. Pain in lower and mid back when bending over. What can I do?

Hi, 24M 5'11 120lbs. No smoking or alcohol. I have had back pain for over a year now. It hurts when I consistently bend over. When it starts hurting, it aches and leaves me stiff. I can walk and lay down without it hurting, haven't triend much running.

I was told my the PT that I need to strengthen it. I'm going back to PT in a few weeks, but wanted to know if there's something else I could do. I guess I'm asking for some good exercises to do.

It's making me involuntarily move weird as well, like I expect my back to hurt so I stiff up.