I had the same feeling last week. It passed. You just have to move with your psychology like a weather pattern--different people have different climates, but we all have stretches of bad weather.
And when you feel that, you start pulling together all the negative points from your past/present/future to rationalize feeling that way. Here's how mine went:
I've already finished my first degree and two years later in back for one more year of prerequisites. I'm really smart, got a full ride my first time around, am kicking butt in these pre-requisites ... but if I'm so great, why am I twenty-five years old with very little money and 6-10 more years of training ahead of me? What have I got to show? and what does the ******* organic Spartan assignment have to do with any goddamn thing? Then the story just keeps spreading--your family, failed relationships, boring classes, uncertain professional futures...
Then I got through a couple quizzes, crammed for some tests, finished my late assignments, laughed at my friends' jokes, got some good news from my advisor, found some songs I liked ... the weather was changing all trough that. I started remembering that some things are under your control and some aren't. I've made some good decisions and bad ones but when I put my mind to things I can usually take names. I'm still moving forward and have something that could be very good for my future--good school around competent people, good work, options ...
Just put yourself in the position to enjoy the good weather, and try not to let the bad weather derail you. It will still suck and you're not going to want to study, but hopefully obligation will push you through to the other side where you can enjoy things and get ready for the next storm, drought, whatever