Writing Blues

I find myself always wanting to write but the instant I either pick up my pen or open a Word document, my mind goes blank. Not cool. I really want to write in Of Religion but I think I need to rework it and well rewrite some scenes. I've been writing in the prequel but still...I feel a blankness. I used to know where it was going but now not so sure. What happened to my creative juices? I used to be able to write chapters in one day now one sentence needs to be dragged out. I miss writing.