Nancy's advise is right on target.
I would image that it is hard to get motivated to exercise after a long day on your feet, so you seem like a perfect candidate for the early morning exercise crowd. For me, if I don't get it done first thing in the morning, most likely it just won't get done. So set the alarm a little earlier and slip out the door for a walk around the neighborhood.
2.5 years, 45 pounds later... 128ish pounds