My early teen years were really rough. I identified with a lot of what you are describing, OP. I don't remember wishing someone would kill me, but i do remember wishing i could just go to sleep and sleep and sleep...maybe for 100 years!
It got better as i got older; and, though i still have challenges and days i get discouraged, i would say that each year truly gets better. Hang in there.
Do you have anyone you can talk to? School counselor maybe? My children have really nice guidance counselors at their schools who are very kind and sympathetic and truly care about the kids. If your relationship with your mom is rough right now, maybe there is someone like that who could help you sort out some of your feelings.
_________________
"Them that don't know him don't like him,
and them that do sometimes don't know how to take him;
He ain't wrong, he's just different,
and his pride won't let him
do things to make you think he's right."
-Ed Bruce