A dream about the end of the world as we know it, whether it is due to an asteroid hitting the earth, a nuclear war, a worldwide pandemic or something else, can symbolize a personal upheaval that is completely changing your life.
Such a dream can be triggered be feeling out of control, possibly due to hormones (puberty, menopause) or personal circumstances (death, divorce, loss of a job).
If you dream that you are alone among strangers at the end of the world, you may be feeling isolated in your waking life.