Need a little advice, please!

Okay, so after a summer full of trips to the zoo, swimming at the pool, and running our buns off, the Walton girls are pretty pooped out. I am also switching grade levels this year, so I've had to re-create a fun classroom atmosphere for first graders while also learning a new curriculum. Needless to say, I'm going into this school year a little exhausted and the craziness hasn't even begun yet. So, here's where I'm in trouble. My husband is forever telling me that I don't know how to relax and do nothing. I thought he was just being silly, until TODAY. I set out this morning to do ABSOLUTELY NOTHING today. No plans, nowhere to go, nothing to do. My goal was to rest up because school starts this week. I know that after meeting my 27 little first graders on Wednesday and explaining school policies and classroom rules, I am going to be ready for bed as soon as I get home. And I'm even more concerned because I don't have Don to lean on if there happens to be a day that I actually need to go right to bed! (It still boggles my mind how single parents survive!)
Back to my "DO NOTHING DAY."
The girls woke me up around 8:00 where I convinced them to stay in my bed to watch cartoons while I caught a few more zzzz's, (operation "DO NOTHING" in full effect).
We finally rolled out of bed to feed the starving fish at 9. We made our way downstairs to eat a nice breakfast together (Plan still in effect).
Then I remembered that I had put laundry in the washing machine last night, so, because I HATE the moldy smell of soaking wet laundry, I ran down to put the clothes in the dryer. This reminded me that the heaping pile of dirty clothes should probably be washed before my crazy week. (Operation "DO NOTHING" is slightly off track...)
After sorting and starting laundry, I head upstairs and remember that I have to print my schedule for my principal by tomorrow. So I head back to the computer where one things leads to another, and I end up doing school work until lunch time (Operation "DO NOTHING" has failed for the morning). I'm feeling dejected.
So, I re-assess and start over. Lunch time. We make mac and cheese, grapes, and teddy grahams for lunch and all sit together to eat. After lunch its my favorite time of day...nap time! Surely this cannot fail!
Ah, but it does. The girls head off dream land and I head down to my new comfy couch with my favorite snuggle pillow. Turn on the tv for some background noise distraction and try to sleep. Out of nowhere, my allergies kick up and I can't stop sneezing. I spend the next 2 hours of blissful sleep time sneezing and rubbing my puffy eyes until I hear the dreaded sound of Molly's feet on the steps (only dreaded because that means nap time is OVER). Operation Do Nothing is wishful thinking at the point. Here is where you come in and I need some advice!
When Don is home, we spend every Sunday afternoon at his parents house. I had told the girls that maybe we would go this afternoon. They don't really remember, but my guilt of not taking them over there and putting Don's parents on the back burner makes my stomach hurt. But, I haven't stopped sneezing, I still have laundry to do, and I have yet to DO NOTHING! Do I fight for my sanity and try to sit and do nothing for the rest of the day? Or do I just call it quits since I haven't been successful so far and head out of the house for a visit? HELP! How can I sit and DO NOTHING without physically stapling my butt to the couch or feeling guilty about doing nothing??