Simple solution?
If you have any sense of conviction or a scrap of determination or willpower you will do the following.
1. Stop drinking/smoking.
2. Start working very hard in school, pay attention to the teacher and take notes. Don't forget to study for tests and prepare for your finals.
3. Treat people like they're human beings, don't just think of them as obstacles.
I can remember a time in my life when I thought similarly, of course I was not nearly as deteriorated, I found that filling the void with work and improving myself in whichever way possible provided me with not only a positive outlook on life, but a greater acceptance of myself and my peers.
In short, I became a better person, and you can too.
This is something you have to do yourself though, if you want a better life, you have to work for it.