What do you mean, exactly, by "all the edits are gone"?
The exported files? Or the information about the changes saved to the database/xmp files?
Since edits are constantly and automatically being saved to the database (catalog) without you needing to do anything, even if the computer crashed all but the last edits should be safely recorded in the catalog file (*.lrcat). However, if the computer did indeed crash with LR open and active, it is likely that a *.lock file would remain in the catalog and previews folder and would have to be deleted before LR can be launched again. So, question 1; did you remove the lock file? Question 2; are you opening the catalog to which the edits were written - presumably an LR 2015 catalog which cannot be opened in LR5 - or are you viewing a new empty catalog that you have now created?
Thank you so much @elie-d ! There was in fact a .lock file that didn't delete, and once I did, all my develop editing reappeared! I appreciate you taking the time to explain that, as it saved me a few days worth of reworking! Cheers!