don't worry kid. I'm 12 years old and i was just as scared as you. There is evidence the world won't end.
1. Mayas never predicted any apocalyptic event since they NEVER clearly said it would be the end. I swear if right now u stepped foot in a Mayan village and asked about 2012, they wouldn't know wat ur talkin about.
2. The Bible clearly states( I'm Catholic and have been going to a Church since i was 6) that ONLY god knows when it will end.
3. If a plant/meteor/asteroid/comet was headed this way it would be able to be seen with the naked eye.
4. Nostradamus never specifcally said the date 2012, and that goes for I ching, mother shipton, and Hopi.
5. Thee have been over 100 predictions of the end.
6. We are so gullible, that NASA had to tell us the world would not end.
7.besides there are going to be earthquakes, floods, rain, snow, and everything in 2012 like there is EVERYyear!
I hope I helped! :D