Sleep Deprivation

About 4.5 hours of sleep last night, and it was choppy. Boy, am I tired.
We all know the effects of sleep deprivation on stress, weight loss and probably diabetes. My fbg this am is 98, higher than it *should* be. For potential pregnancy, they want me below 90 in the am. I can achieve that on these dosages of metformin and lantus, IF I get enough sleep and don't eat after 8 pm. Both of those appear to be unreachable goals this last week or two.
Yesterday was telecommute day. I started doing that again on Wednesdays. With a 45 min commute in each direction, it makes a huge difference. Plus with various other time savings, I can sleep in 1:20 longer. Ahhhhh.
My son also sleeps in, since I guess he doesn't hear me moving around. (Da Kane takes him to daycare, so theoretically he is able to sleep in everyday) He slept until 8, about 2 hours longer than normal for a weekday, about normal for Mommy being home. Daycare said he slept about 30 mins longer at naptime too. It's counter-intuitive, but the better rested toddlers are, the more they nap.
This is yet another source of Mommy guilt. 85% of the growth hormone is released during sleep. By contributing to his sleep deprivation, am I keeping him from growing?
Perhaps my biggest worry is that I will fall asleep at the wheel. Out here in the west, we do 80- 85 mph on the Interstate (75 is the official limit). Dozing off at that speed is a death sentence.
I am trying to cut out caffiene after 4 pm, but when I get home at 5 and Da Kane has made a fresh pot, it's hard to resist.
I also need Da Kane to keep the tv sound lower, since he usually stays up until midnight or so and is slightly hard of hearing, at least compared to me. He'll be watching down in the family room, and I can hear the tv - not make out the words, but hear the noise. When I'm having trouble sleeping, the quieter and darker it can be, the better.
I switched to the 7-4 shift last year from 8-5, I knew I was trading an hour of sleep for another hour with my son. A trade well worth it, but when I get on an insomnia binge like this week, it's 2-4 hours lost a night and I can't handle it. I do love the traffic at the earlier hour though, and it does save me some time because of that. Of course, leaving before everyone else in the dept means a lot of days I don't actually leave at 4.
Must go shower and wake up and function and move on out.
P.S. Da Kane is Hawaiian for The Man, and refers to my husband.
P.P.S. Made it into work safely. If it's not too hot today, I will take a nap in my car at lunchtime.