how about cutting back for a few weeks?
ie. paper plates are AWESOME, grab 1 box/basket per child and put it up on the washer or dryer...keep out 3 jamies, 10 undies and a few socks, all in the basket. everything else in some sort of box/bag (trash bag,e ven) and stash in the basement or garage or attic. then you can breathe...and slowly work through things. i'd do the same with toys and games and puzzles...keep out 1-2 of each and bag up the rest for a while. then you can have a clean, clear space about you in thehouse. its amazing how much this can give you a clear head and increased motivation.
for the closet...can they hang clothes up high and play underneath? or can you put up a tension shower curtain rod somewhere else and keep clothes there, so again, you can have clean and clear space to start with?