the very first thing i would do if i were you is practice pushing my left shoulder down as soon as i had the bow drawn. this one very act will encourage your body to straighten up. push that shoulder down and your left arm will naturally extend out instead of wanting to go left - straightening your bow up. the bow will be farther away from you, and that will allow you to straighten your body up. those are the very first things i'd work on anyway. then, aim with your shoulders instead of moving your bow arm up and down.