Do you also dream that you wake up late for work/school? This is a classic symptom of midbrain damage (most likely a tumor) affecting one's sense of time. Unfortunately, there is no treatment, so you will soon develop dementia and die. You've probably only got a year to live, maybe two if you're lucky.
Just kidding.
Just kidding.
Even this is kidding, I experienced this too. I came late for work and there is something important that day in our office that I need to wake early. But suddenly i will realized it's just a dream. OMG thanks God.