It's not finding a suitable disease that's the problem when researching for House fanfic -- there are tons of them out there. It's the differential diagnosis stuff that'll drive you nuts, because then you have to research a whole bunch of other diseases as well. And if, like me, you really don't like research to begin with and find yourself easily frustrated not knowing where to start (or stop, for that matter)... well, all there is to say is "urgh".
However, I think I managed to get through the worst of it today. I have several pages of scribbled notes (my handwriting is really unspeakable these days, it's pathetic how seldom I pick up a pen any more) and a whole bunch of ideas floating around in my brain.
And if this sounds suspiciously like I'm working on a sequel to "Galatea", then, um... you might be right about that.