Hikerchick, if you have one day (or even part of the day)that you can set aside to prep for the week, it will help you immensely. There are a bunch of make ahead mix recipes posted on here that are timesavers, and healthier and cheaper versions of what ou get at the store. You could make some of them up. precook some food and keep them in your fridge, ready to heat up when you need.
When you come home from the grocery store, wash all your produce right away and store it proper, and cut up the celery, carrots broccoli etc. so it is there waiting for you when you need it--so much of a time saver, and since it is handy, when you have the munchies, since it is right there, you could grab the veggies rather than that convenient cookie or whatever.
think big batches and leftovers when you do cook. Your committed anyways, might as well add in some extra for a few more meals. leftovers are awesome!!, nd if it looks like it will be in the fridge for more than a few days, make up some TV dinners and throw in the freezer. as others say--crockpots can become your best friend. when I have a busy day here at the farm, knowing I won't have the time or energy to prepare supper, I dumpa a bunch of stuff in the pot in the morning, set it to low all day, and then pig out. Soups are great to have in the fridge too--just put a bowl in the microwave and good to go.
That's about all I can think of right now.