A Serious Lack of Motivation

I have a Serious Lack of Motivation. I'm not sure how to cure it. There are 10,000 things that I could/should be doing at work, but I can't motivate myself to do them. I think it's probably because I am not invested in this job at all. It never has been my favorite thing, but I would do it. I would worry, stress, plan and at least put up a good front. It has just been ridiculously hard since having the baby. I don't really care what happens here; there is an extreme amount of work that needs done and I feel like everything I worked to do here in the last 2 years has come completely unraveled in the semester I was gone. I know that no matter what I will not return here in the fall, so I just don't care if things get done or not. That's horrible. It makes me a bad person and a bad teacher, but I just can't seem to get going. I'm an experienced enough teacher that I can do my band classes without a detailed lesson plan, although- if I'm being real - I need to do better with the advanced band. However, we have been hovering at around 50% attendance in there, so why should I care if they don't? (Again, that's the bad teacher in me.) My beginning classes have between 2 and 4 kids in them, so that's easy enough. Individualized assignments, float around, help.....blah, blah. I have taught Music Appreciation for 3 years now so I can just look back at what I did last year and everything else is cleaning up someone else's mess that I already cleaned up ONCE. I'm not up for doing it again. So, if anyone has some spare motivation or finds some in the street, pass it my direction. I've got some stuff that needs done.