I haven't had a nightmare in eight years, despite having anxiety, lots of brain activity and eating before bed despite having stress or even sleeping in uncomfortable positions all of those are the leading causes for nightmares and those all happen excessively to me so tell me why I can't sleep at night tell me why I can only sleep when I'm so tired I pass out perhaps there's a reason or maybe it's because every time I go to sleep, I dream and every time I wake up, I wake up into a nightmare.