you can hit the ball well over 1/2 of your maximum distance with only half a back swing. the further and longer you swing the club the more chance to cock it up or for it to go off track. 0.01 degree off multiplied by hitting it 200 yards means it's well off down range.
dont try and John Daly it wrapping the club around you 5 times, just go back halfway work on bringing it through right, using your hip rotation to provide the punch and stare at the floor until the ball is out of your sight. lifting your head to 'chase where the ball went and see if its a good shot' just changes your posture and you hit too high on the ball or over it etc.
dont try and hit the ball high either, the club face is what gives the ball its lift from rolling up it, it's club selection and positioning the ball in your stance that defines how the shot is shaped/what course it takes.
golf is pretty much all technique and mental game you don't have to be particularly phsyically strong to hit decent distances (+ medium distances straight is much better than long distances to the side), being both mentally strong in terms of focus and discipline and logically strong in the type of shot selected are the main differences in golfer skill.
if you have a decent coach at a big club or range, he likely has access to the camera equipment to watch back your swing and see your errors/inconsistencies which is a nice way to understand what you are being told. often they will tell you about your grip or your stance and changing this when you stand to the ball just feels so weird you just have to keep doing it until it is the new norm.