Fear of Finishing?

I'm about two, maybe three scenes away from finishing my latest manuscript (not the sequel to Grime. That's on tap for next month). But holy smokes. In the past forty-five minutes that I should have been working, I've:

stared at the pencil container spun the chair in circles deleted emails from my i-phone sharpened my pencils

I don't get this. I'm almost done—shouldn't my brain be rushing for the finish line? Shouldn't I be exalting on how close "the end" is? Makes me wonder...