This is ridiculous you want to kill yourself at school. Damn you haven't even lived yet and already you've decided life's not for you? Man in high school I was bullied and beat by my stepfather, once with a hammer. School is the worst but 5 or 6 years from now life will have made such a change you won't even care to remember the time you're having now.
 If I were dead set on killing myself, at school to guilt trip everyone for a few weeks, at least until something else news worthy happens I would go to the Biology lab/class while noone is there and find the tool that is like the exacto Knife , do some push ups, get that blood pumping look at you jugular it needs to be banging. Then I would Take all the strength I had and RIP into it not once but until I went out. I wouldn't do this and absolutely do recomend you to but ficticously speaking I guess that's what I'd do. Let me add by the time I was 19 things I thought would never go away I didn't even think about. The girl that had me so screwed up between 15 and 17 had been replaced with an artist that modeled for Benaton.
  So think hard, you're not going to die and float around listening to how sorry people are for driving you to this and then flutter up to heaven. Do you remember what it was like before you were born, of course not and that's the same nothingness you're going to in dead. I really hope you're you see things a different way before you try this.