This is different from other suggestions; prevention rather than treating the symptom with a hopeful cure:
Exercise during the day! There IS a huge correlation between physical activity and good sleep. Our bodies are meant to be used, strenuously, even while pregnant (barring some kind of medical condition). Exercise will also help your blood sugar issues.
Simply walk at a good pace for at least 30 minutes, and before bed stretch out all major muscles. Yoga - even just a 20-minute tape that your son can 'join' you for- helps calm the nervous system and body.
Then, you can still drink the teas and take the homeopathic remedies suggested, but you may not need them!
In addition to excercise, my favorite sleep aid (which I know you can't do now but when your hubby returns) is sex and/or a good, deep leg (and body if you can get it) massage. I get super twitchy legs while pregnant- drives me nuts!
Good luck, get moving and work that energy out! Surprisingly, exercise will also keep you oxygenated & energized during the day, and you just might sleep like a baby...er...the proverbial baby, anyways!