Renaming folder as .nosync deleted all synced files

I have a folder, a very important folder with two years worth of work in it, that was uploaded to the iCloud. I dowloaded the folder (containing various images) to load these into a project as I needed to print the project. Half way through the upload process the file started uploading themselves again to the iCloud. It was about 3/4 uploaded when I noticed. I renamed the folder with a .nosync extension in the hope to stop this and download the images again but after doing so I found that 3/4 of the files had been deleted. They have also been deleted from my iCloud Drive. Please help.