Why is writing so hard sometimes?

In the past week I’ve been staring at my computer pretty much all day and what do I have to show for it?

10 measly pages!?!?!

I guess to some that’s considered a lot but why can I sometimes sit down and do those same ten pages in a matter of hours and sometimes it takes me three days? Andn I don’t even think they’re 10 good pages!

I don’t know what the problem is.

I’m excited about this story. Really excited. I don’t know which direction I want it to go in, but I never do so that shouldn’t be slowing me down.

I hate this. I hate the teeth pulling, what feels like the opening of a vein to get things down on paper…

Hell, I can’t even manage to get the words to come out in a blog post.

So, somebody tell me, how do I make this go away. I’ve already given myself permission to write crap (and oh boy, am I). I want to get back with the flow. Won’t someone out there wave their magic wand and make it so?