please help me

so this is more of a rant, if you take the time to read thank you so much bc i know no one knows me or anything like that. but lately i've been really sad, i'm a junior in high school and recently i went through something really hard that didn't affect me but it completely changed my perspective of my best friend and this guy that goes to my school, long story short he cheated on my good friend with my best friend and i'm the only one who knows. i feel like my best friend (however much we love each other) takes advantage of me bc i am pretty quiet and easygoing and she expects me to follow her around and do as she says and i'm soooo tired of it. i feel like i can't trust her bc she doesn't care about this girl that the boy cheated on with her. and she has unfortunately convinced me to let it go unnoticed. it makes me sick. besides that, i have lots of homework and a heavy work load this year, i also work at a restaurant on weekends and sometimes school days so i'm stressed. i feel like i have absolutely no one to talk to who will truly understand and support me. i'm insecure bc i've never had a bf, guys have really used me in the past and i feel like i'm ugly and worthless and people take advantage of me lol. sorry this is so depressing but i just feel sooo hopeless. like i question the point of living my life if it's gonna be this painful to the point of me crying myself to sleep at night. well if you made it this far thank you, i just needed to get this off my chest.