Being myself in front of friends?

so im a girl thats 16 yrs old and i used to have a problem with worrying about what others think of me especially in school and i still have that problem but im working on it and im also trying to come out of my own closet and become more open and less shy and pretty much just be myself.. i want to start new sometimes and be a new person and live life how i want it without regretting anything and put a good impression on myself in front of people but the only thing thats stopping me is my friends who know everything about me and all my flaws and the mistakes i made.. everytime i try to become who i wanna be, a better me, i feel like my friends still know that old me which i dont like at all.. :( im trying to change but its hard cause of them!