How do you get rid of insecurity? in my very own shower thoughts and other stuff

sometimes i think of myself of an insecure person. i always try not to be but there are some people i dont stand up on and i dont say my honest opinion. its very hard for me to describe it. i want to be myself and its weird because i hate phony people more than anyone but still i sometimes think that i am kind of fake myself. i want to change that. its important for me to be confident about myself and i shouldnt care what people think about me but its hard because it takes alot of guts to do that. if youre reading this it would mean alot to me if you could maybe give me advice on how to get rid of that insecurity. Am i around the wrong people? i dont really feel comfortable with the people im with but that shouldnt take away my confidence, should it?