So, I've been in a panic about what has happened to my photos. I have found just about all of them (and thankfully photos from 2005-March 2011 are still in iPhoto, and I have a lot of photos since March 2011 on my laptop). I am just concerned about how my photo catalog got corrupted in the first place, and what precautions to take going forward so it doesn't happen again. I even attempted to restore my computer to an earlier version on Friday of last week, but the "restore" button on my Mac is grayed out. Don't know what that's all about either.
This issue is overwhelming me at the moment because I have SO many photos to deal with. Going forward I'm going to be relentless about deleting. I don't even want to deal with this Lightroom issue right now.