[@Loony] That's exactly what's been happening for me.  Like for some reason my sleep schedule has been totally out of whack since this semester started, getting more than maybe 5 hours of sleep is almost impossible for me, which leads to me getting nothing productive done in class and feeling like crap about myself all day.  It really kills my motivation and now I feel buried under all the stuff I have to do, but I'm still going to keep trying.