Marathon-lasting exhaustion

I've been training for a marathon for several months, and now have had two horridly pathetic weeks of training and the third is off to a poor start, with lingering flu symptoms. I have to get this back in order or will risk limping through the 26.2 miles on May 9th. At 5:07PM tonight, I already felt ready for bed. Does it mean I'm a grandma? Do I need to get my pajamas on? Or is it just recovering from essentially 19 days of company, which I loved but was also difficult to keep up working full time and sight-seeing and visiting. I have hit the wall.

If I go to bed at 6:00, I'll surely wake up at midnight and beat myself up for crashing like an infant. So instead, I will prop myself against the couch and wait for the sun to dip in the sky. Perhaps I'll lay out my clothes for tomorrow so I can get up a little later.

I am soooooo tired!