I have been sleeping for 4-5 hours a night for about a year. When I go to bed I don't get the tired drift of feeling I feel wide awake. But i will suddenly sleep. I often wake in the night anything fron 10 mins to 45 mins. I feel wide awake. I do manage to get to sleep again. I normally wake for the day between 4.30am and 5.30 am. I will occasionally sleep 7 or 8hrs once or twice a month.
I know I'm going through peri menopause I think it could be linked to that