I wonder if this is the same thing that I suffered from as a (mature) student - even though I enjoyed my course and got good marks, when an essay had to be written, suddenly anything seemed better than putting bum on seat and getting on with it. Those where the times when the oven got cleaned, the toilet unblocked etc. Anything seemed preferable to what I really needed to be doing!!!
Actually, I get the same thing every year when I have to search for cheaper car insurance, breakdown cover, electricity and so on. I get an awful feeling of dread and even though I can't put them out of my head, I put off doing any of these things until I absolutely have to.