I used to be like that as well. I hate that you feel that way. I would start with focusing on something you love in this world, a passion, and focus on that. And build up that passion and find confidence with that, and hopefully that may transcend into other areas in your life. Confidence is really important to how we present ourselves. I hope that helps in some way. I would recommend seeing a counselor just so that you can talk about this more in depth with someone. Going to a counselor does not mean there's anything wrong with you, like many people seem to believe.
I hope you work through this!
