One of the things I do is keep the tv/radio on. I read somewhere that helps... Something about just hearing people talking. There are also puzzle toys where the pup has to "work" to get to the treats. Magnus and Zoey LOVES the "stuff n throw" balls.
Amazon.com: Stuff n? Throw Ball, Medium, Blue:...
If you're going back to teaching, does that mean you'll be gone for 8+ hrs every day? Will you be able to come home for a short walk?