Hi
@Arnie Pye !
Just a thought -
melatonin is thought to be the trigger of "winter depression" (seasonal affective disorder?). Because of the missing light during daytime in winter, melatonin is not broken down sufficiently. Result: depression. Now with your sleeping pattern you simply might not get enough sun light to break down all of the melatonin you took. When you take another pill the next day, the melatonin adds up and makes you drowsy and depressed...
It's 3:49 am here, I'm still not tired enough to go to bed. Outside the snow is falling, so no sunshine this day, too...