Classic case of playing golf swing instead of golf. You can't play golf if you're entire mind is devoted to every single aspect of your swing. You can work on all that stuff on the range, that is where golf swing is played. How I stopped doing this was getting reps in on the range, but when I got to the course turning this off and focusing on the golf shot, not the golf swing. I have built a routine. Stand behind the ball, take in the shot, the wind, the lie and pick a target in the distance, then pick an intermediate target on the ground in front of the ball for alignment purposes. Step up to the ball and take one practice swing with no swing thoughts. The only note I take during the practice swing is where the club impacts the ground. This helps me put the ball in the right position in my stance (especially useful on weird lies like sidehill, ball above or below feet, etc.). Next set the club head behind the ball pointed at the intermediate target, set my feet, then set my hands, and do a last little shuffle with my feet to make sure I feel comfortable over the ball and then just take a nice hard swing at it. Generally the results are fine and from time to time I hit a bad shot, but that's golf. You must realize no matter how good you get you're not going to hit every shot perfectly so expecting bad shots should be part of your thought process. A bad shot does not mean you need to make swing changes it just means you hit a bad shot. The only swing adjustment I allow myself to make during a round is tempo. I can swing harder or slower to find the speed where I am making solid contact that day, but I am not going to make any adjustments to posture, arm position, new grip, attempting to hit a certain swing path, etc. The entire thought process during a round is on strategy, target, and alignment and that is it.