Believe it or not tori, that feeling comes to every one of us when studying. It's just exhaustion.
I always think the worst mistake many people make is not sticking to study routines. OK, I realise you've started your studies, (like 10 years ago). I'm just saying that, there needs to be a time for study and a time for play.
But never take a break from the study. If you're routine is 2 hours per evening then those two hours are strictly for study. Doesn't matter what's on TV. Visitors will need to come back later. No alcohol. and so on.
Think the reason you've only had two replies however is that most people know where you're at and would just say the same thing.
But believe me, when you've finished, however long it takes, it'll be worth it.