Winners and Losers
In sport there are always going to be winners and losers . In reality it is not always the team or the athletes ability that is the difference between winners and losers it has a lot to do with the attitude their belief in themselves are they in the zone. None of this is skill it is all the 6 inches between their ears. 
Regardless of which school you went to or how well educated you are when it comes to sport if yo wish to be the best that you can be it comes down to hard work. Not only developing the right skill set but being able to execute them under pressure when things are not going to plan and there is a need for a change to get the game going in your favor.
This calls for a level of mental toughness be 100% focused on the goal confident in your ability to carry out the job at hand and relaxed at the same time. Being tense and nervous will get you no where fast.
Having a mentor or someone close who understands your situation is a great help as they can offer some kind words of advice to help you through those tough times. Not necessarily on how you play the game but some words of encouragement that will impact on your own self confidence and your own personal belief in yourself.
Winners and Losers
As we all cant win all the time it is important that you look at the positives and not the negatives. Take apart of your game that went well and think of how you could do the same with other parts of your game that did not go to plan on the day.
Going back to the basics is often overlooked. We are inclined to make things to complicated as most sports can be brought back to a hand full of basics be it golf, basketball, football or tiddly winks. Run through some of the easier basics then move onto the ones you have a challenge with that way you are likely to have more confidence when you get onto the more difficult tasks.