Help I screwed up badly in the develop module

The Undo or Command Z does not work in this situation even when LrC has not been shutdown. I  Fortunately the .nef and .xmp files were in the trash I copied them with finder into a folder on my hard drive and then imported the first few and much to my delight all of the edits were saved with the files. The only thing I lost was the history listing of each of the edits but I can always make any additional edits as the develop panel has the results of all of the edits. This morning I 'added' all of the images into the catalog and moved the recovered folder to where I want it using the LrC Library module. It was so satisfying to watch the previews being built after import and seeing each thumbnail one by one reflect all of the edits.  I think what saved me was the catalog preference setting for metadata to 'automatically write changes to xmp'
Using the Autosync feature can be a great time saver but it can also be very risky if not turned off immediately after desired changes are applied - this is the mistake I made along with not paying close attention to dialog boxes when they pop up and not backing up my work more frequently rather then after many hours of work.