hello, firefox stores backups of your bookmarks for ten days on your computer - please refer to the following help article: Recover lost or missing Bookmarks

This does not really help, I am not able to find any of the bookmarks. As well If I tell the sync to sync from the cloud and overwrite the ones I have on the computer no new bookmarks show up.

when you go to firefox > help > troubleshooting information > show profile folder > bookmarksbackups are there .json files containing recent dates in there? if so please copy those files and paste them on your desktop. afterwards try to import one of those files in the bookmarks library.

You can check the size of the JSON backups in the bookmarkbackups to see if there is a large(r) file that looks promising and then try to restore the bookmarks from that file.
Be sure to backup all JSON backup in that folder to be sure not to lose any of them.

You can use this button to go to the Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder

• http://kb.mozillazine.org/Backing_up_and_restoring_bookmarks_-_Firefox

The json files there are no use, all the same... I have however managed to pull from a backup of an external drive most of the bookmarks.

I am however not happy how the sync would simply delete all the bookmarks, And there would be no way to pull the bookmarks from the cloud as they where, as it seemed to backup no bookmarks into the cloud and overwrite all the original ones. Making it not so save.