Self confidence means self assuredness to do something. To build self confidence the first focus is to define multiple levels of your responsibilities. Work on each one, one by one because you can not focus on more than one at a time. Focus to gain 100% clarity on what you want to do and how to do that. It is important to gain clarity on the process. And then only start practicing till it becomes a working belief. For any activity to become a habit and thus your self confidence in doing that, you must practice at least for 28 days.
The second focus is to question your belief system and eliminate your self-limiting beliefs. Your belief system is based on your past experiences. The situation in the present can be similar but not the same. People normally are programmed to confuse memory or imagination with facts which is directly detrimental to your productivity and thus your self confidence.
The third focus is to learn to convert negative approaches into positive ones. Just for example worry is a negative expression while concern is the positive alternative to worry. You will be surprised that while using the word concern in your language you feel positive and committed.
And finally the need is to live as a self confident person at all times. Life is full of different situations. so accept every so called problem as a situation only. Gather correct and relevant information. Define all the pros and cons and clearly define the acceptable outcome. Then only develop the strategic planning to deal with the situation. Accepting and living in the present prepares you to face and manage each and every situation in your life.