Input lag

[SOVIET PARTY SHOES]

So, I've owned this game for quite some time with virtually no problems. However, when I started it up today I've had horrible input lag even in single player! It takes several seconds to register that my cursor is hovering over my units or that I've given an order and renders the game completely unplayable. This problem has never show up before and I haven't changed any settings on the game or on my computer.
I am running windows 8
Radeon HD 7870
Radeon FX-8350 (x8)