Recently I found myself with, effectively, writer's block. I had an idea, but couldn't come up with anything leading from it. In effect the idea was just a bunch of words sitting there mocking me, or at least that's what it seemed like.
I got through it by going back and thinking about, and trying to put down on paper, what had interested me about the subject in the first place. And also writing down my anxiety about having writer's block, plus a bunch of stuff implied by that. Lo and behold, I started getting more ideas after that.
It's kind of like having stomach flu or something. Once you lean over and puke your guts out, you feel amazingly better.