Post Holiday/Pre-third-baby Blues

I'm not entirely sure that the title of this blog is accurate, however, I'm not sure exactly what to call it so here goes nothing. I am SOOOO monstrously getting nervous about having three babies. I am into the third trimester tired. It is different from first trimester tired in that if I can just even sit down for half an hour or nap for a little bit I feel better. That was easy with baby number one since I only had me to worry about and could sleep whenever I wanted. It was even pretty easy with baby number two since baby number one was still taking 3 or 4 good naps a day as well. Baby number three I am finding significantly more challenging since baby number 1 has all but given up naps and baby number 2 never took good naps to begin with. So, I know I'm whining, but, I'm TIRED!!! And, I'm fat. I refused to make a weight loss resolution this year as it wasn't fair that 1/4 of the year I would be in the largest stage of my pregnancy. I need to be fit though and I desperately need more energy. I would not be nearly as worried about my physical condition if I weren't a widow to the weather half of the year, but last night as i sat on the recliner with a baby on each flank of the one still in-utero trying desperately to get them to sleep while they tried desperately not to co-operate, I asked half-teary of my father "Where in the world does the third one go???" He chuckled and had no good advice! So, I need to be prepared for the even fewer hours of rest and crazier days ahead. Mentally (don't even want to know how to prepare that way) and physically. I know I can't diet although I've tried to be careful about my snacking substituting apples for chocolate and grapes for oatmeal cream pies (only about 3/4 success rate thus far) but I need an exercise routine. Everything I read cautions heart rate monitoring and body temp regulation. And since I don't have enough time to even get a nap, I certainly don't have loads of internet research time at my disposal either. So, I turn to you my blogging community for advice on how to safely stay fit and be able to keep up with the insanity!!! Any and all advice is GREATLY appreciated! (I also don't have the ability to go to the gym due to lack of gyms in my proximity and the kid factor, so home stuff is best...even better when it involves rolling around on the floor looking silly so that the kid factor can be fully involved!) Hope everyone is having a great new year and thanks in advance for your input!