Help me. i dont want to feel this way anymore?

im 15 turning 16 in about a month.im a girl and for as long as i can remember ive hated life. im always sad or angry and i havent had a good night sleep for years. it takes me forever to fall asleep and once i do i wake up like an hour later and i have to start all over again trying to fall asleep. its hard for me to get close to people because im always afraid thier gonna hurt me. for i few years now ive not just only liked boys but ive also liked girls too. i think i might be bi. my parents only seem to care about their own problems. my dad always lie to get other people to feel sorry for him and i hate that. i live with my mom and she is loseing her house so she always says that we have no money but she still buys ciggs and wine. my "friends" talk to me in school but they never talk to me outside of school. sometimes i get so upset i cut myself and dont even relize it till afterward. i dont want to talk to parents because im afraid theyll get mad at me or dissapointed or that theyll think im doing it for attention or to make there life harder. and i dont want to tell any of my friends because i might weird them out or make them unconfterable so they wont talk to me. and i dont want to tell any teachers or concelers at school because theyll blow it out of proprotion and i dont want to make a big deal about it. Also my sister always get what she wants and im not exaggerating. my dad idk y but always says yes to her and my mom does bc she has giving up on fighting with her bc my sister is just that much of a *****. she always calls me fat or ugly and that i have no friends and no one loves me. if she not saying mean thinks shes hitting me or pushing me or scrathing me with her nails that leave gross cuts. i just dont no what to do anymore but i dont what to do anything stupied that will hurt of stress out my family. how do i stop feeling like this? sorry about the spelling :/