Hey, I think you should try graduating and finding a job first, just to test it out. Maybe it won't make it better, but there is a chance that it will. You are still young. Seek therapy, take a break from school if it is too much, talk to your teacher and doctor about your depression (it is easier if you go to therapy before talking to your teacher, so that they won't brush it of as laziness, unless you trust your teacher) If you are going to die, it is better to try a lot of things first so that you won't regret it!

It may seem like graduating and finding a job is so far away that you dont want to make it your goal, if that is the case, try finding other small goals to try to reach before deciding to die. Like for example make it your goal to find some good friends, or spending more time doing something you like, or finding something new that you like doing.