Easy stuff first, there should be a bunch of about 20 emoticons to the left of the white screen you write on to post a message, just click on one & it comes up in the body of your message where the line (for the next letter) is. :d
no, I haven't considered those as causes, but as everyone is different perhaps you could try a diet specific to each of these problems (msg & hypoglyceamia) & if the break through symptoms decrease then you could try reducing the meds (slowly) & see what happens. Remember though that natural alternatives (including diet) take up to 2 months to show improvements.
having had alot of health problems etc etc, including a daughter at 33 & a son at 39 1/2 (he's now 9 & hell on wheels pretty much 24/7) I have some idea of the situation you're in & frankly insomnia, anxiety, stress, depression etc is hardly surprising. A pre-schooler at your age & with health issues for both you & your husband is enough on its own to cause these problems.

Below are some things which might help, you, husband & also dealing with your son.
1) ces machines (about $200-300 worth it in reduction of symptoms & savings in cost of meds) you use these twice a day for about 60 minutes & they help all of the symtoms you describe & some others inc. Pain (for your husband) - so he might be able to get some relief & reduce cost of his meds too!! :d try dynamind.Com
2) some natural supplements/vitamins to help with stress reduction etc etc inc. Vitamin b's, gingko, sam-e, 5htp(tryptophan), dhea.
3) you possibly need some fresh air (i saw you mentioned that you exercise but is it relaxing??) try walking & maybe take your son with you & spend some time at a park sometimes, this should help tire him as well as giving him time with you!! Exercise never tired either of my kids but people tell me it can work!!

he (& you by getting time out & maybe meeting people closer your age who also have young kids - if you're lucky) might also benefit from joining a sport group, my son plays cricket, soccer & football. Or your son might prefer to learn music?
Anyway, goodluck.