Fading into and out of sleep as you are trying to work – how well I know that feeling! I remember being 'phoned by one of my clients and asked if there was something wrong with my computer.
I replied "I don't think so, why do you ask?"
"Because I have an email here from you times at 3 o'clock in the morning."
I said "Yes, that would be about right".
There was a long pause, then he said "You're working too hard" and put the 'phone down.
Fair comment – I did have a lot of work in at that time, but when you're running your own business, you have to do the work when it's there, because tomorrow it might not be.