Dropping a camer and a slight bounce are certainly not the same thing by any means. The reality is that this lense (and camera) has many moving parts that can be effected by a jarring incident. Any of the 12 or 13 elements that make up the lense could be out of wack or shattered causing the camera to be inoperable. If you move the camera around can you hear any noise from inside? If so something is broken. Otherwise it may well be a displaced lens element and is a repair candidate. I seriously doubt that there is anything that can be done without dissasembeling the camera so it needs to go into the shop.
I hope the problem is repairable and you get your camera up and running soon. Best of luck to you.