Left analog stick not working properly?

I have a Playstation style controller for my PC, that’s about 3 years old. I was playing a game (from STEAM, Samurai Warriors 5) and i was using the left analog stick to move my fighter around the battlefield for most of my game today. All of a sudden, the character won’t move w/ the stick any more (can still use the d-pad to move) but the stick can still move the cursor around in the game menus. Can someone please help?