This is how I felt after Thanksgiving, and several rounds of assorted "oh, I never eat this way so what the hell" meals.
I only made it 3 miles. I bitched, I moaned, I whined. I shuffled along begrudgingly. I hated life. It was 65 degrees and I thought I was going to melt.
And this, as always, is when I remember that what I eat profoundly affects how I run.
So here's my advice, kids: junk food in moderation. Don't tell yourself it's a "good idea to get it all out of the way at once" or "I've already come this far. What else have I been wanting to eat lately?"