Whatever the outcome of the game, always stay calm. Even when you lost, you should not lose your self-control. In an effort to gain back the money that they've lost, individuals who lost tend to bet even more. It is not advantageous to take such measures. What you need to do is to let yourself cool down first before betting again, next time.
When you made some mistakes, don't worry. This is only normal and likely to happen if you're a beginner. It would be a learning experience which will let you to grow and be more proficient in gambling.