It's the intermittent short bursts of sleep that exhaust me more than complete insomnia, and sadly, this is where I am at thesedays. Several months ago I was lucky to average 2-3 hours a night, consistently, and while very dabilitating long term, it truly amazed me (and anyone else I confessed to) how functional I was able to remain, as long as I was busy and active.
Nowadays I am probably averaging a total of 4-5 hours, but it comes in bouts of about half an hour to an hour, separated by long, often widely awake and highly aroused periods, which end in sudden overwhelming exhaustion etc. This pattern usually starts at about 9.30-10pm at night and can continue until around 7am, depending on my schedule. It is truly exhausting me and leaves me feeling like the proverbial hit and run victim. Crazy, but I almost miss my tried and true insomnia...