I don't know how to ask for help/worried about repercussions (kind of long)?

try to find a free counseling program around you I know I have a bunch around me. Ask your school and see if they can recommend any. It definitely sounds like you need help. But if you don't wanna talk to your parents then I suggest you try this. If not talk to your parents and explain that you don't wanna come home but you know you need help they will see responsibility if you do that. Good luck.