be less insecure

Pretty much my whole life i think, i’ve always thought that people are better than me, that they have more right to be here than i do. I don’t know why, cos i had a happy normal childhood and everything, so there’s no reason for it.
Also I’m worried all the time about what other people think of me, like sometimes i think “oh i’d better say this now ‘cos they’re watching”, or “i can’t say that, they’ll think i’m uncool” and stuff like that and it’s so annoying.