90% of the fears which are in you are irrational. The best is to take steps to stretch your comfort zone. This is a simple training process. Suppose you are afraid of heights. Go to the exact limit you can comfortably stand. Stay there for a while without moving. After that take a minute step forward and stop. Step back. And step forward again. Step back.
The second day, stretch it slightly further. and so on.
Taming your fear means taming an instinctual response. the key to your success lies in repetition. This means that you have to invest at least some time and focus to get rid of whatever scares you. You can immensely stretch your confidence by taking these small steps.