I work at a university, too, a public, though not as a professor. I've known enough faculty, including my wife, to gather that it can be rather disillusioning those first weeks, but that for most it gets much better, often within the first year.

It's our first week, too, and today I saw a freshman wearing a t-shirt that said "I never liked you anyway." I thought it set the wrong tone for the beginning of her first semester. She should at least wait until after midterms.

I hope the depression lifts soon and that the teaching becomes worthwhile once you start identifying the students whose lives you're positively affecting. They can be the ones you least expect in the beginning!