If you're getting mad at your kid for something they did you are making the game about you and you need to CTFD. The game is not about you. You are investing in it on behalf of your son, and it's up to him to reap the return. If you can't deal with failure because you feel like your investment is being wasted, then either pull the plug or stay away, and stop viewing the results. Nothing and no one is perfect. Baseball is truly a game of failure.
Most kids are trying their best, unless they truly don't want to be there and are looking for an excuse to exit the sport.
In either case, it's not about you and you need to calm down. Try talking to your player. Yelling and getting mad for imperfection is selfish behavior.
Thankfully, by 16U or so most parents have learned just how difficult it is to achieve any level of success on the field and they are grateful for the opportunity, rather than trying to steer the process. The complainers and schemers wash out more and more the higher you go. Thank god.