Some heel shots are caused because at set up you are too close to the ball causing your arms to start inside your shoulders
Practice your entire swing in super slow motion, this will allow your mind to focus on the correct muscle movements needed instead of trying to make your brain work on the correct movement while you are swinging, just do it don't think it
Do not put pressure on yourself as you approach the final few holes and have a chance to break a personal milestone, take each hole on the course as a separate game and try to win that hole, then move on to the next one disregarding your previous scores