The best way to build confidence is to sing in front of a group of 5-6 people. Select the 5-6 people to be friends or family who like your songs. Ask one of them to record your practices and then watch them later. You will be able to find your own glitches there. Work on them! Try increasing the number of audiences and gradually you will get better! I have done this.
In the process of getting those songs recorded I figured out some of them that were really good. We uploaded some videos to youtube and we could also send entries one of the online music portals. You could try doing it too. You might just get some gigs to perform!
