Here's an exercise if you feel overwhelmed and behind.
Make a list of major deadlines.
Go to the office on a weekend or evening. Make a list of things you have to do. Now immediately just whittle away at it. Write that letter of wreckomendation or that course description. Order those textbooks for next semester. Fire off those emails.
Then, make a shorter list for Monday or whenever you'll be in the office next, and another list for things that can wait until the next working day after that. Make sure the lists include items relating to major deadlines.