Did you try hitting the 'Default' button in Controls?
Try browsing to the '..\Documents\Larian Studios' folder and renaming the 'Divinity Original Sin' subfolder.
This folder contains the saved games, configuration files and a level cache folder. Deleting or renaming it will get the game to recreate it on startup; playing the game from a different Windows user account would effectively do the same thing.
After that, start the game, create a new profile and check the options. If that fixes it, just copy your saved games from the renamed folder into the savegames folder(s) of the newly created profile(s).
