How can I get myself "re-set" so I can actually sleep at night again?

I've always been a natural night owl. I'd much rather sleep most of the day and be up and doing stuff at night. Unfortunately, most of the rest of the world doesn't function on my schedule, aside from a few gas stations and diners. And Walmart :/ Having kids means being up at the time I'd rather be going to bed, to get them ready and out the door.

So, the last few weeks, my schedule has been like this:

Can't sleep at night. No matter how tired I may be, I can't fall asleep. Get tired enough to sleep around 5am. Have to be up at 6.15am, so I just stay up. Finally get to sleep about 7.30am, sleep for 2-4 hours, usually interrupted by phone calls. Get up, caffeinate, try to get stuff done before kids get home. Once kids are all picked up, given snacks, and occupied, I tend to doze off until around 6pm, when I make dinner and get everyone's bedtime routine going. By then, no matter how tired I may be, I'm wide awake and trying to catch up on doing stuff I didn't during the day, and spend some time with my guys. I'll probably be up and doing stuff (cleaning, cooking prep, showering, etc) until 2am, at which point I'll get in bed, be unable to sleep, end up reading or internetting until 5am, have to stay up til 6.15am... rinse and repeat.

Last night, I crashed. Hard. Fell asleep around 6pm (not by design) after getting no more than 4 hours sleep in the last 48 hours. Woke up briefly to say goodnight to kids, and crashed again. Woke up at 2am, so hungry I couldn't ignore it, and by the time I ate, I was wide awake again. So I've been up since 2am, and am just now getting tired...

ARGH! What do? How can I break this fucked up cycle? Or should I just give in to it and do whatever I can at night? I don't like taking sleeping medication, because I don't like being out so hard I can't get up to deal with a sick kid or whatever. Husband is very often not home until the wee hours, so I feel like I have to be ready to deal with stuff. I sleep better when I sleep at Other-Husband's, but I can't stay there every night.

HALP!