be more confident in myself

Growing up, I was a pretty confident kid. Later on, in my teens up til now, I have lost that confidence. I have a lot of things I want to change about myself, and if I can manage to be more confident I will abolish a lot of personal conflicts. If I were more confident I could be a better friend, be a role model, be beautiful, be smart, be worth your time, and be happy. ..so why don’t I do it already?? ..it’s really hard. The hardest thing in life is to be confident. SURE you can say you just will be from now on, but the second someone (anyone, even a good friend) says something to you, you begin doubting yourself again or you go back to feeling like shit because whatever happened hurt your feelings and it’s really hard to keep it all going in a good way. Regardless, I want to be confident in myself. I don’t know how to do this, but maybe someone will offer me some help