Because high school isn't the end. Those bullies don't mean crap when you leave school. It gets better. Life gets better. You'll have a job and be successful and they will still be at the school... Just as janitors.
Because.. Why would you want to take your own life? That just show the people bullying you that they could get to you. The best thing you can do is just keep on going and keep a smile on your face even when your hurting inside. Don't give them the satisfaction of breaking you down. That's exactly what they want. And once you stop giving it them they'll eventually just leave you alone.
You are the bigger person. You not only go through everyday routines, studying, chores, etc. but also deal with them. And you will come out on top. The catty popular girl at my high school is now the main hostess at a local restaurant. She's been working there for 20 years now. The geeky kid who was always bullied is now one of the most sought after, world class plastic surgeon. You will conquer these bullies and you will end up more successful and happier.