Ultimately reason, facts and logic are more powerful than fear. The fear only seems powerful, but it isn’t, and once you start to ‘get’ this, it becomes easier. Fear is an indicator that you are in danger—not necessarily physical danger, but that your values are in danger in some way. In many cases, for you, fear is actually an indication of your low self-esteem. Your self-esteem is threatened because you might disappoint or displease someone. As your self-esteem gets stronger, by questioning and acting against these mistaken premises, the fear diminishes and in some cases goes away. This is the direct result of your continuing efforts to challenge and correct your mistaken premises, which manifest in your feelings.
The central purpose for you psychologically isn’t to reduce fear so much as grow in self-esteem and self-respect, independence. As these grow, the fear goes away.