How important is psychology to your performance? Is this something you even consider? Ask yourself, what do you think when someone mentions psychology to you? Do you know what it means? Do you assume that there must be something "wrong" with a person for them to see a psychologist?
Within sport I hear a lot of people tell me how interesting they find psychology when I tell them what I do, yet how many of those people actually consider psychology when it comes to their own performance? When you have a performance coming up, whether that is in the sporting arena, or maybe just giving a presentation at work, or having a job interview, how do you prepare? Does psychology come into that preparation? When it comes to the actual performance...again, what role does psychology play?
Now, ask yourself, do you find that you think negatively about an upcoming performance, anxiety setting it, worrying about what might happen? Do you find on the morning of that performance you are going to the toilet frequently, maybe can't stomach a proper breakfast? What about during the performance? How do you handle the nerves then? Then after the performance, what happens? Do you reflect on what went well and what didn't go so well? Chances are, even if you performed well that there is still room for improvement, but do you consider this? Do you learn from your experiences?
If you find that you keep experiencing the same negative symptoms, then it sounds like you keep responding to those negative thoughts in the same way, and haven't learned how to manage the anxiety when it kicks in. If the same thing keeps happening then I'd imagine that reflection isn't something you do as a matter of course. These are all things that psychology helps with...psychology is about understanding our thoughts, emotions, and behaviour, and learning ways of changing how we react to certain situations if they are problematic. Within a performance setting this allows us to maximise our performance. Now ask yourself again, how important is psychology?