The world was ending, in one of the most terrifying ways the world could end. (to me)?

I don't know what your dream means. I don't know whether the world is going to end the way you described it or not. But I would ask this: Have you watched a movie about the end of the world? Have you talked about this with someone? Have you thought about it before having this dream? ..because sometimes (I don't know how this works) what occupies our mind spills over into a dream. So, we think about something and then later have a dream about whatever we were thinking earlier. I know this, because it happened to me before.