How do you push past the severe depression from being isolated?

Essentially just the title. I've been completely isolated from the 5th grade onward, and I'm supposed to be in grade 10. However, I am a couple years behind. My mother refuses to send me back to public school, so I have no opportunities to socialize. Since I'm basically left alone all day, I wake up everyday and struggle between staying awake (and feeling ridiculously depressed, to the point of being unable to even look at my schoolwork,) or attempting to sleep it off and feeling disgusting about it afterwards. Any suggestions? I'm not a stupid kid, I know I'd be excelling if I had never been pulled out of school. And my mother refuses to acknowledge my severe depression, she either gets mad at me and says it's somehow my fault I have no friends, or says she "relates" to me, as she has no friends either. (Which is a complete lie by the way, she does have friends. Plus, she's allowed to socialize every day at work.)