Photos are gone, files on Dropbox are empty

Hello

i have the dropbox basic abo. It is connected to my computer because of my pictures. I do a photobook on my computer. So now i wanted to add some new pictures to the book and 530 pictures are missing. they are gone. So i went on to a computer expert to see, why. He said, that my dropbox maybe changed the pathway of the imge, so the photobook app cant find it anymore.

So i wanted to look out for these photos. I logged myself in on the webpage of dropbox and neerly all files are empty. But the file on the desktop is empty too. How can this happen and why?

My dropbox is full, i konow that. But where are the pictures? I have a file on the desktop with pictures i took of my dad. I uploaded them in November 23. The file is synchronized (there is a green button on it). But the file on my desktop is empty and the file on the dropbox website is empty... Why??? Where are these pictures.

I just want to find and download them back to the computer, because i want to delet the dropbox. thats what the expert told me to do. But I have nothing to download.