in the closet? bi??

hi i’m 16 and starting to get really confused w my sexuality. ive been starting to think that i was bi since last summer but never told anyone and don’t know how i’d even mention it. i’m so confused and lost rn and i need advice/help. what’s more scary is i feel like one of my closest friends won’t accept me and i’m so scared i’ve been hiding it from everyone including myself but i just can’t do it anymore.