Go get on the freakin treadmill.
You are completely dressed, running shoes on, and all you have to do is walk into the next room and hop right on.
Remember how you've worked out every day for the past 15 days? And how you feel 100% better than you did 2 weeks ago? You notice how your legs look stronger, you have more energy, feel better mentally, etc, etc, etc???
So what is the problem?
Yes, your house is a wreck. And yes, you have work to do. And yes, it is freezing and rainy outside and you really want to finish your book.
HOWEVER - did you see the back page of the newspaper today? The page that has your sister's engagement announcement on it?
Yep, that little dose of excitement means you have about 9 weeks before that wedding. You cannot afford to take days off from exercise just because you don't feel like it.
So go DO IT.
I did it. And felt great. Just once I'd like to feel crappy after exercise, so maybe I would have an excuse not to do it if I didn't want to.