As far I am concerned, I think that other words are needed to this question and I like to share with all of you how I think this question also can be asked "HOW HAVE YOU BUILT AND STRENGTHENED YOUR SELF CONFIDENCE? Let me explain why.
We, as a human being, are extremely complex and one part of this complex system is our metal capacity to boost any wish. Self-confidence will not depend of what or how we think about our self, more than what or how we have reached our self-goals.
For example in my case, some months before I started to see myself fatter and started to get struggle with my life I felt very uncomfortable with my cheeks, belly, arms etc, so what is the common answer to solve this? Go to the gym!!! All people do that and I hate with all my heart repeat incessantly actions that all people use to do, but I prefer get ride my prejudices and reveal what happen beyond the gym.
I got an enormous surprise with all things learned just with going to gym per one month and I don't mean surprise to my body. The positive mental effect that you gain just doing things that you have never thought to do strengthen the most important muscle: YOUR BRAIN. I know that I have just reduce 1 kilo in one month but I feel that I have gained all forces to re-conquer the world.
It does not matter what is your goals or what do you want to reach ALWAYS, listen ALWAYS there have been a positive side effect that boost you to do more and this is the meaningful of self-esteem. To become a president is not an overnight success, have you even though how many goals have to been beaten to become a president?
Weak up early, learn another language, go to the gym, speak in public, become an amateur chef, read books, paint, dance, strength your mind your body ...just tell me what and how many goals have you beaten and I tell you how your self-esteem is.