What does my dream mean?- world ending.?

I dreamt last night I was in a public place with lots of people around either a beach or in a field and all of a sudden it went black like the sun had went out and knew it was the end of the world. All of a sudden I realized I couldn't breath and felt myself dying like the oxygen was running out. I wasn't afraid just accepting - then woke up. But has really stuck in my since. Really disturbing. Any idea what this might mean?