I am having trouble maintaining posture through my downswing and impact. I hit the ball solid, but it looks really weird. As I start my downswing, my shoulders drop towards my hips and continues through impact. I also am making contact leaning behind the ball. Does anyone have any suggestions on why this is happening or how to fix it? I'm 6'4 but all my clubs are custom fit so I don't think it has to do with my height.