Anxiety, depression and the search for sleep

I imagine 2 o'clock in the morning looks quite different for you and I. I envy you, hopefully, being able to be fast asleep and dreaming during the wee hours of the morning. Rest assured, most days I'll be laying in bed, mind racing and asking a million questions at once, of varying levels of sensibility. Did I lock the front door? What happens if someone breaks in through the front window? Is the handbrake on? What happens after we die? Did I do a good enough job at work today? Will the cat run away in the night? In the cold light of day, as I write this, I can see that these q...