Hey I love that flylady website and I can relate to the overwhelming feelings when it comes to clutter. Our house IS on the market and I have to "try" and keep it clean and picked up in case we get someone that wants to look at the place. I will tell you I make lists now and I feel really good crossing things off as I go. Tackle it one piece or one area at a time. Try the pantry if you have one or a couple of "junk" drawers. I am constantly cleaning out our 2 junk drawers.
Also take it easy and take a break when you need to. Don't overdue. It will all get done.
