Over the years I have grown increasingly appreciative of how the mind impacts the performance of physical tasks, including shooting.
Strengthen your mind through some simple drills:
1. Dry fire
-Deliberately run down a mental checklist prior to breaking the shot and following through.
-Stance, grip, aiming, breathing, trigger control, follow through
-Deliberately focus on maintaining a calm mind and ignoring everything but maintaining the fundamentals.
2. Live / dry grouping drill
-At a range, use a SMALL target and mix dry fire with live fire.
-4 dry fires, 1 live round, 4 dry, 1 live etc..
-Shoot as tight as you possibly can and deliberately focus on maintaining a calm mind and ignoring everything but maintaining and applying the fundamentals.
3. Ball / dummy drill
-Dry fire a few times concentrating again on a calm mind and perfect form.
-Have a buddy load your firearm with either a live round, or an empty chamber.
-Engage the target accordingly while concentrating on maintaining a calm mind and perfect form.
I can't overemphasize the mental aspect of shooting, or any physical task for that matter, enough.
Repetition helps condition the mind, and frequency helps maintain any conditioning effect. Train intensely and effectively, train frequently, and you will more easily develop and maintain the right mindset.
Shooters can also develop anticipation issues due to poor fundamentals that make the recoil seem greater than it is, which is easily fixed by simple grip / stance corrections. Once the physical issue is fixed, the mental issue are much easier to address.
Practice, practice, practice.