Lost muse, search inspiration

Have you ever had that feeling that you're at a dead end, that you've lost your muse? I have to write a material, the limit term is off and I can't figure out in my tired mind how can I finish this paper. I'm really tired and my imagination searches some sleep after that long deprivation. I need to rest and to relax but I don't want to until I'm done with this. There must be a way to do it right and on time (as in the possible time, like in ... postponed I guess). Is there a recipe?