I'm not sure how this happened as I have successfully done this before. I exported images to my desktop from Lightroom, then with batch in photoshop added a watermark "proof" to the images so that I could post on my website. When I went back in Lightroom the "proof" started appering on every image I click on and there was three lines with a ? in the top right corner. Now every image I click it shows the "proof" Ugh! How do I revert back to the original Lightroom file. If I can't do that I still have the card, but the images are greyed out and it says there are duplicates on my computer. Can I re import them?
I suspect you may have 'Exported' the images with the Lightroom option set in the Export dialog to [Add to This Catalog]
So what you are seeing is the Exported photos in the Catalog changing and the "three lines !" indicating a Metadata 'conflict' (or change) caused by the Photoshop batch action.
Trying to re-import the originals will not work..
Look, or search, in the 'All Photographs' Grid view and I am sure you will find both the Originals and the Exported photos (ie. Lr is identifying the originals already in the catalog and preventing 'duplicates'.)
A second thought-
If your originals were JPG files and you exported to the same folder as originals and told Lr to 'Over-write' then Photoshop IS over-writing your originals. (Do not delete files from the camera card just yet until problem is sorted- make backups!!)