Are you happy, well-rounded? (dealing w/ depression/lack of motivation)
ithayer: I struggled with a something very similar (complete inability to work, not knowing what makes me happy), a few things I learned seem relevant: 
1) Don't assume what other people are thinking or feeling (about anything, but in this case, many other people do go through similar things)
2) Happiness and fulfillment has a lot to do with expectations (intrinsic as well as external). Understand what those are and where they come from. 
3) Talk to people, read, and if that's not enough, get help (seems like you're doing that). You'll probably learn something about yourself.I can recommend "The Feeling Good Handbook" by David Burns (Stanford), which is about cognitive therapy [also described in other places]. It may not be exactly accurate for your situation, and those types of books may sound silly (I thought so before reading it), but I've found some of the techniques useful.