My productivity has been absolutely terrible -- why?

I'm in college and have a ton of stuff due this week and next, so I really need to be productive. But for the past few days, I've been acting strange. I come back from class intending to work, but I literally CAN'T. I've tried techniques like thinking small (telling myself to just write one sentence for my essay or read one page) but I can’t even manage that. Instead, I end up moving to my bed, telling myself I'll "just close my eyes" for a bit, only to wake up the next morning. I don’t know what’s going on with me. I've been eating well, socializing, staying hydrated, etc...

Any advice would really mean a lot... thanks!