I have previously had operations on both shoulders leaving them and my right arm weaker than normal. I struggle controlling the length of my backswing. In my swing, my first aim is to have the left shoulder reach the chin. At that stage, my left arm is still straight and relatively parallel to the ground. My problem is that my mind thinks I have to swing longer to achieve more power. I tend to do this and know that it is achieved by my left arm then breaking down and bending. My swing becomes longer and lazy and UCHHHH! How can I fix this problem and where should I aim to swing my driver and 3 wood in particular?