Flashing In-Game Menus

About a week ago or more, my in-game menus started flashing the entire game (like the graphics for them are having trouble loading or something) and my FPS went up, but the actual game graphics themselves are fine and I have no lag. I had to turn my graphics way down to lower my FPS to a more reasonable number. I'm not sure why this started. I didn't do anything different and don't have anything extra running/open on my computer, and I've already tried restarting my computer a few times. Nothing seems to help it. ...To be clear, what's flashing is things like the menu window, such as when you're in the store or editing your sound or graphics, the map, the abilities menu, and the game score menu. It's just a constant flickering.