Nothing is more stimulating for your self-confidence than accomplishing something you dread. E.g. go parachuting; confronting a tiger; getting stuck in quicksand or jumping a cleft. Well, actually it does not have to be that extreme, but the feeling of accomplishing something really dreadful is unbelievable and you will feel invincible.
The feeling can be intoxicating and you want more. Fear is a fantastic feeling and it is an important part of our natural defence. Fear releases adrenaline and activates your fight-or-flight response. Adrenaline creates instant action and motion; thus, fear is energy; fear is motivation to action. Enjoy it, because the feeling of overcoming fear is fantastic.
Some people seem to go fearless through life getting all what they want. But know that every day of their life they face fears! The difference is that they have found a way to deal with fear. The problem is not fear itself, the problem is that you doubt whether you will win the fight. Instead you choose flight and that choice will only increase your doubt and the fear becomes worse; you will end up in constant fear and anxiety.
You need to trust yourself and your abilities to fight whatever you have to confront. Trust that you can escape the tiger; trust that the parachute will bring you safe to the ground; trust that you can do whatever it takes to take action and move on in life. If you always choose to flee then you will never get what you want. Life is difficult for all of us, but you need to face it or it will become even more difficult.
Start confronting fears; do not listen to doubt; bite your teeth and leap into fight. Maybe you get a few scratches in the fight but you will win if you believe in yourself and trust that you can do it.
Fighting fear is never fun while fighting; the feeling of invincibility comes after the fight. That is the feeling that will prepare you for the next fight. If you have some fights waiting that seem overwhelming then take some other fights and accumulate strength for the really big fight. None of your fears are impossible to overcome, you just have to believe and find the strength to leap into the fight instead of flight.