Issues with Core Sleep

Over the past couple months, I've gotten used to a variation of 5-10 hours of sleep per night. I know this sounds like pretty extreme fluctuation. Usually it doesn't change that much from night-to-night though. I tend more to go through a week-long period where I sleep about 9-11 hours each night and then maybe a week where I sleep about 6-7 hours a night. This uncovers yet another motivation for everyman/polyphasic sleeping:
I want to be on a standard schedule where I know how much sleep I need and can count on filling the rest of the time with work.

I'm sick of needing to study the morning of a test and not being able to wake up before 11am! Anyway... The fact that my sleep schedule is fairly constant from day-to-day but varies over weeks/months suggests that little shifts by half an hour to an hour are really easy to deal with, but large shifts just don't pan out well.

Maybe this is why the past 2 nights I haven't been able to fall into a 3-hour core sleep cycle. I wake up just fine when my alarm goes off (drinking enough water before I go to sleep helps, because then I have to pee and that gives me a reason to get out of bed!). But with only 3 hours of sleep, I feel much different than I do when I get 8 hours of sleep. I'm much less conscious at first, I feel hazed, dizzy, headachey, physically jittery, etc.

As soon as I start thinking, my first thought has been: go back to bed! Second thought: Don't do it! Third thought: Ok, just set an alarm for a couple more hours or so. This will be a good compromise.

That last voice in my head has won out the past 2 nights. I've never been able to pull all-nighters effectively or get by on close to no sleep (this doesn't include party nights and recovery the next day...) in a way that allows me to work the next day. Maybe I just need to shift slowly.

The Everyman is supposed to be a great transition into the uberman polyphasic cycle; maybe a slow gradient of sleep changes will produce the best results as far as A) getting me into the cycle, B) making sure I can maintain it, C)keeping me mentally sane and not hating myself for screwing with my sleeping.

Last night's plan: 2:30-6
Actual sleep: 2:30-6 6-7 7-8
Each little increment there represents a time that I set and alarm, got up, rationalized, and crashed out on the futon again.

But I feel pretty good right now, and that was an aggregate of 5.5 hours last night. Not bad when I slept ~9 each night last week. From here, I'll trim about a half hour every 2 days for the next week or so. With luck, I'll be down to the core of 3 hours per night and solidly napping through the day!