Literally No Scripts are loading

All the scripts in my project aren't loading, they all say "the associated script could not be loaded, please fix any compile errors and assign a valid script". This includes the default Unity ones like 3rd person controlled that I have not touched.

I feel like I've tried everything: deleting the last custom scripts, reimporting, deleting the library files, and it's still stuck like this. I don't want to lose progress, does anyone have ideas?