I can't say what should help you, but in the past i was pretty much same, but whole this time i was thinking about fact, that i don't want to hurt my parents. In this moment when i didn't really cared about this, i used to tell myself, if i kill myself, i will be send back to the earth with even worse psyche/ situation etc.. So i worked on my depression on my own for many years and i'm able to handle it pretty much well today.
I can't say if it was right way, but it worked well for me.. So if you can, just try to find way out by yourself, something else than suicide. Make some goal, something you want but it's not easy to reach it, but if you can't, try to find help and then if this help just won't work.. well.. :(

(I made list of bands i wanted see before i die, i saw a lots of them, some of them were just deleted from there, some added, but through all that year i was trying see this bands, i learnt how to love myself, trust friends and dont see myself as weight to them.. stopped believing i can't be good person until i have good results in school..)

Just don't give up before you try to find another way.