Everyone is good at something. Discover the things at which you excel, focus on your talents. Express yourself, whether it is through writing, art, music etc. Find something you enjoy- we all have it! Give yourself permission to take pride in them. Give credit to your successes. Appreciate your talents. The truth is, inferiority is a state of mind in which you have declared yourself a victim. You should not allow yourself to be victimised!
Everyone is born with talents and strengths, so stop feeding yourself with lies or allowing others or situations to feed you with lies that you are nothing. You have it- you are equipped with talents and strengths, all you need to do is to develop and excel in them.
If it is difficult to identify your abilities or what you think you love to do, think about things others do that you would like to do too and take some lessons, do a research about them, read about them. I found out that when you are following your passion, you feel unique and fulfilled, all of which can help build your self confidence. Also, following your passion is therapeutic, helps you master your skills, which to a large extent increases your chances of meeting great opportunities.