LiveCycle crashing - corrupted file

I have a relatively complex dynamic survey form that's about a third of the way created. It's taken me several days to figure out the basic structure for Likert scale questions -- size of fields, subforms, etc -- and to remember all the scripting I need to make comment fields appear when requested, and to figure out the master pages that repeat header fields on subsequent pages after being filled in on the first page. I've finally gotten to the stage where I'm simply repeating the basic Likert scale structure and filling in the correct question for each repetition.
 
Today I've had LiveCycle crash at least half a dozen times when I've copied & pasted the subform that gets repeated for each question (the crash happens on the paste operation). I thought I'd figured out that I needed to copy & paste the smaller elements within each subform, and then wrap them up into a new subform; this seemed to be working for the last few questions.
 
So I've spent a lot of time waiting for LC to load again today...it's a little frustrating, but it's always opened OK, just slowly.
 
But the last time it crashed -- pasting one of the smaller chunks -- it seems to have corrupted the file. It won't open in LC, and it won't open on its own as a PDF.
 
HELP!!!!
 
Are there any tricks for recovering the file? Can I get in behind the scenes to a text file somehow and figure out what's broken? Can I do something with XML to recover what I've done?
 
I'm not a power programmer or anything, but I can find my way around under the hood if I need to, and I REALLY don't want to have to recreate it from scratch at this point!
 
I thought I was doing really well saving the file after each operation, so at least I stopped losing the last few things I'd done. But now I guess I may have to start saving intermediate copies of my files every so often, just in case I lose everything like this!