Have you ever dug yourself into a deep pit and then realized you didn't bring a ladder? That's how I'm feeling right now as I strive to figure out what to do with the middle of my story.
I took some advice from the conference and ran with it, so now I've got this major event in the middle of my story that sounds cool on the surface, until I try to figure out all the practical details of it. Hmmmm. I keep hoping if I let it percolate a bit, some sudden burst of inspiration will occur to me. I remind myself that Stephen King was once afraid he was going to lose his manuscript of The Stand when he was like 500 pages into it, because his plot line was getting too confusing and his character cast was too cumbersome (which is not my problem at the moment.) Then he got this idea on a plane ride and literally scribbled it down on a cocktail napkin because he was so afraid he'd forget it. And presto--this brainstorm solved all his plot and character problems and he finished the rest of the mammoth story off in a relatively short period of time and it is often called his best work.
So I maintain hope. It can still work.