ACTING STUPID

so i am in 7th and i feel like i can't be myself and i don know myself i don't know my personality so i keep acting stupid and trying to fit in which is not me i feel it.. i just wanna be me and be likeable and stop acting stupid my bff calls me

stupid bc i make myself look dumb and sometimes i get bad grades and i pretend i don't care or something.. please give me advise