Unless you installed a boat load of stuff between now and when you first started having the FF problem, you shouldn’t lose anything, except Windows updates that were done.
I’ve never had a problem myself, losing stuff. Your personal files should all remain intact and anything you’ve worked on, even up to today, should still all be there.
They were there, I forgot what happened when I did that “restore to the last working system 7” or something like that. I turned on my desktop computer and a black page of stuff came up saying the hard drive was not doing something right and asked if I wanted to restore to a previous working system or something and said yes ...