Hi, Mulan-
I'm so sorry this is happening to you. I know what it's like to have chronic depression- I've had mine for almost 7 years.
Have you talked to anyone about this? You'll find that the people you don't think can handle it can take surprisingly a lot.
There are a lot of people that can help you- teachers, parents, siblings, doctors... talk to someone you trust. Just know that we're all behind you and we want to help.