Can anyone help me?

I'm depressed
I don't know if its real depression that can be fixed with pills
or if I'm just sad all the time
But it sucks
I cut my self and then I felt better
but i don't wanna do that because it scares the shit out of me
Sometimes I feel like I want to die
When I got into a fight with my friend and we told the teacher about the fight
I was in hysterics and I told them
They said I was being silly and that there where people in much worse situations who were alive
Basically they called my wanting to die selfish
I don't think they took me seriously
I'm scared because I don't want to die
I don't want to hurt any of my friends or family
I don't want to leave my mom because she's living with just me
and doesn't have a a boyfriend
I don't want to hurt anyone but myself
but sometimes I just want to sleep forever and ever and never wake up
I want to tell someone but I'm afraid they'll call me selfish too