What gives?

Had a kick ASS workout yesterday.
Actually we got two workouts in. Over 7 miles in total. I'm pleased.
working out with friends is much better than the tread or the gym.
Today however, I pooped out. It was all I could do to get to three miles.
I don't understand it.
I'm suped up on protein, not hungry, just toast this morning as far as carbs go...what gives?
Anywho, I only "get" to work four days and then I am going home!!
I need the money but I dread coming to NJ.
I have to make some changes.
I'm booked next week for just enough work to justify not staying in NJ.
If I would just make the leap.
What is holding me back?
Ta'