renpy should have another folder named like the game inside, the saves have the page number and position that indicate where they are on the load save screen, something like "24-6-LT1.save", at least on windows...
still, chances are renpy is smart enough to have saves somewhere even if you delete your current build and download another one
also, if you are on the itch launcher, doesn't the game prompt you to run it or open the saves folder whenever you wanna play?
well, try downloading the game on your desktop and see if it automatically finds and shows your saves when you try to load (so no itch launcher), if it does, your saves should be safe... and you can probably just play like that, versions don't have to be kept for saves to transfer over, so it's not like you'll have dozens of gigabytes eaten by ToS.
after that, if you reaaally want to use the itch launcher, you can overwrite your saves and delete the build over there to see if a reinstall fixes it, but that's for later, try what i said above.
