Your source data is false. No civilization has predicted that day as the end of the world. If you have a reference to cite where you heard or read this, then please present it. Otherwise, you only pass along false hoax gossip.
The Sun has not gone anywhere. This phenomenon of which you speak is AS SEEN FROM EARTH ONLY. This is due to Earth's axial tilt which makes things in space APPEAR to line up when in fact they do not.
The Sun's location is currently 50 light years ABOVE the Milky Way ecliptic and is moving FURTHER from the ecliptic - not closer to it.
This VISUAL alignment is a common misconception and is the major hoax propelling 2012. Do not be misled by the fraudulent claims from those who are out to profit from deceiving the misinformed and uneducated on the topic.
The visual alignment which you speak of has occurred many times in the last hundreds of years on different dates in our calendar. Nothing has ever happened. This date will be no different. There is nothing mysterious about this phenomenon.