lower back hip pain

I’ve had this pain for, I would say 8 years, but it is getting worse, when I lay on the floor on my left side and try to lift my leg up(like i’m going to do a leg lift) my hip? pops out or something, but it’s very painful and then it seems to pop back in and the pain goes away. Also when I lay on a hard flat surface like the floor my hip will pop out. I don’t know whats causing the pain. It seems to help if I strech my lower back and hip, but the pain is always there and its extremly painful when mu hip”pops out and the back in again”.