After a lot of time and after a few tries, I finally recovered all my photographs from the bad backup strategy I had. (You can read about that here)
What I end up doing was copying all photo’s one by one to a correct folder (year/month) and sort them, when a specific photo was already in the correct folder, I just deleted it and moved on to the next photo. It only took a few hours to do it this way, and I am pretty sure I have all the photo’s I wanted to keep.
The next step now is of course setting up a good backup strategy and keep that going without getting duplicate photo’s or loosing photo’s. I still need to think about that, but for now I will once in a while copy my bible library to an external harddrive.