For future occasions, you do not need to - you actively should not - ever re-import photos after something like this. Just get files back into the computer (ideally into the exact same place) if they have got deleted; or fix LR's wrong 'addressing' for anything which has become moved from where it was before.
At the moment you have NOT lost your editing history for these images. The Catalog has got a record of it all.
You just currently have two different instances of each image in your Catalog:
- the first is from your first import, with edits, but pointing to a disk location (A) where that image file is no longer present.
- The second is from your second import, which behaved as a brand new image - so has no edits - pointing to a different disk location (B) where that image file can now be found.
Unfortunately, LR will not let you redirect the first lot of thumbnails, with edits, from A to B - because that second lot of unedited thumbnails will block that from happening.
You now have two alternative options:
- Remove the newly imported (unedited) versions of these images from the Catalog by pressing Delete - making sure you do NOT choose to delete files from disk - then go to the older versions' location in the Folders panel, context-click, Find Missing Folder and browse to the new location of that. Do this for the common folder which contains them all.
- Move the files concerned outside of LR, from where they are now, to the location pointed to by the older versions of these images - IOW, back to the exact place they were before. Doing this will "wake up" those older versions with the edits, back to full function - while the newer (redundant) versions will become orphaned. Then the newer versions can be deleted from the Catalog.