Oh Filth, where art thou?

I've been having a bit of a run on fic ideas recently. And when I say a run, I mean dozens of the damned things. There's so much work-in-progress knocking around my hard-drive at the moment it's starting to get embarrassing. I've got half-written stories in many of my fandoms at the moment: Einstein and Eddington [William/Arthur angst!fluff]; [State of Play [Cal/Stephen]; Torchwood [Jack/Rhys]; Being Human [Mitchell/George PWP and Mitchell/Herrick/OFC in a pre-series historical hinted slash-fic set in 1920s London]; and latest being a Muse fic [obvious pairing is obvious], even more surprising because I didn't think I'd ever be going back down that particular bandom alley.

Thing is, I think I can see where all of this fic is falling down, and it's been the same for all my fic of late. I can't do the filth. The preamble is there, I've got a flow going on with the descriptive stuff, but when it comes down to the unfing, my reservoirs run dry. Thinking about it, the same thing's been happening with the folks with whom online chat usually descends into porn. It isn't. When it gets around to it, I just either lose interest or inspiration.

I don't know what the hell is happening to me. How can I be a Filthgoblin without the filth?