All I can say to you all is 'I feel your pain' .
It became a bit of a joke with the DSs when we were all still under one roof, but I do wonder if there is a slightly genetic thing going on too.
My Dad was a bad sleeper, but was a very busy man, and seemed able to cope so long as he had his afternoon snooze on a Sunday.
I have been known to manage for months on 4-5 hours (if I was lucky) with no ill effect, but tended to nod off for an hour in the armchair at weekends.
And DS1, from the age of 0, only managed 4-5 hours in every 24 although a very contented, smiley little chap. He is still the same 32 years later, and has been known to go 3 days with possibly 2-3 hrs sleep, and his eldest boy DGC1, is following the same pattern.
The only saving grace for me these days, being on my own, is that no matter what the hour, I can find something on the TV, or muck about on the laptop doing crosswords or playing games, which help to make my eyes tired, and so help me get a couple more hours later on.
I think my worst problem at the moment is that is half-term. Normally I am on the go from 6.30am to at least 6pm, sometimes 9pm if I'm going on to one of the other PT jobs, so I tend to sleep better on those days, or just pass out, not sure which lol.
But hey, I got another 2 hours early this morning, and am now up and ready to be doing....I do have a busy day ahead today, so maybe I can catch up a bit tonight.
Hope you all get some sleep too