Does the game work with a new save file? This feels like a thing that's not caused by the game itself?
Are you sure you're not pressing the ctrl to hide text? This really is the first time I've heard about a problem like this. It really feels like it's a PC side problem, like something is slowing it down. Have you updated your drivers? Have you tried playing the game as an administrator?
I'm really sorry, I don't know how to help :(