You have to take your arms and shoulders out of the swing. To swing with you arms tense would mean you would have to plan the timing of the wrist cock release and that cannot be done. It has to happen naturally. Try standing and just swinging the club about a foot off the ground. Shift your weight to the back foot, make a relaxed back swing then shift you weight to the front foot with the arms and shoulders totally relaxed. This will pull your hips around toward the target. Your torso will turn and bring your shoulders and arms into action. Took me forever to get this. the momentum of your body turning toward the target will create the swing and the weight of the arms and club will bring you around so your belt buckle is finished facing the target and you rear foot is up on the toe. Swing with weight and body. Take the arms out of it. You will hit the ball farther with less effort than you probably have so far.