the girl could represent your female self, and your subcontinents using her to project that image on. another option could be there's something about that girl you wish you were more like. example, say she's got really amazing art skills and you've been trying to improve yours. the dream is making the parallel that you want art skills like her.
the apocalypse just means one part of your life is coming to an end while another is beginning. perhaps you're moving, changing your major, meeting new friends, whatever it is in your life, you are starting a new chapter in it.
your third eye hurting once you woke up means you might have been using it in some way, and as a result you strained it. myself i would try and remember every detail about the dream and interpret it, you might of been seeing something important in that dream.