Any luck with this?
Sounds like overwhelm ... which I know all too well for my own issues. I need to break things down and really try to block out the big picture stuff for some things.
Maybe you could try grabbing an item -- any item -- and take it to the kitchen table (or wherever) and deal with it there. So that you're not so visually and emotionally distracted.
If it doesn't take long, you could grab a very little slice of a pile and do the same.