In my experience having shot competitive NRA Precision (bullseye) for 30 years this not at all that unusual. In fact, it's fairly common. There are names coined for it, "chicken finger", fear of a bad shot, "target panic" etc. As you can imagine, the condition is magnified in pistol shooting.
Mental toughness in a bigger part of competitive and target shooting than many realize. The really good shooters have ice in their veins and have mastered match / target pressure with iron clad focus on the shot at hand. They can block out a poor shot and totally focus on the shot at hand.
When it comes to match shooting, the more matches you shoot the better you should be able to deal with match pressure. One technique I used in a match was not to look in the spotting scope during slow fire until the string was completed. The idea is so that you are totally focused on fundamentals and don't get distracted with the score of the shot or rattled if it's a bad shot. This is not recommended for practice since you should be calling your shots and trying to learn to improve your master of the fundamentals. But it has worked for me during a match.
Another technique is to mentally repeat your firing checklist each shot. In pistol shooting I would say, front sight focus, positive trigger action, follow through each and every shot. This keeps your mind focused on the shot at hand and helps block out other distractions. Incidentally such a technique can work in hunting shots too.
Visualization is another technique - visualizing the perfect shot. Often used in sports psychology.
Then there is the technique of convincing yourself that this is just a hobby - it's supposed to be fun not a job. When you make a poor shot, try to diagnose the reason. Treat a poor shot as an opportunity to learn, not a catastrophe. I learned long time ago to keep a range book and keep notes on each range session. It's a good way to learn and improve.
Because shooting at its base in an athletic endeavor, you will have ups and downs because of the bio-rhythm cycles of your body. Some disciplines minimize this effect by limiting the human element such as shooting off a bench with a front and rear rest but even this manner of shooting is subject to bio-rhythm cycles. The more the human element is involved, the more the effect of biorhythm. Precision pistol is one of the most difficult because you're using one hand standing with no artificial support.
