After a disappointing shot, you need to move on. You can analyze later but not during play. Here is another strategy to try on for size.
Pick an inanimate object on the course to serve as a "wastebasket" where you will toss all of your errors. Choose a spot just off the fairway and behind you or another player's cart. Whenever you mess up, wad up an imaginary piece of paper. Focus on the mashing of this paper as you take 2-3 rhythmic, measured breaths, then toss it in
to your wastebasket. Say a word out loud, like "reset", to get more of your senses involved. Let go of the past and move on with confidence as you make a 3-pointer into your mistake wastebasket.