Alright. While I was taking pictures, I was resting my camera on a Nendoroid box to gain some stability. While my lens was zooming (AF), I felt some force around the lens. Then I realized that I was resting the focus thing right on the box, but it didn't feel like it broke or anything though.
Then I realized that my lens has trouble auto-focusing. Just keeps rotating back and forth (not much, just a tiny bit). Also, my camera doesn't even tell me the focus points anymore in the view finder (the dots should blink/light up red and stays red when it finds the points).
I'd dismount the lens, clean all the contacts, and re-mount it. Switch camera/lens (depending on models) to manual focus mode and give the lens a run from min to max and back again. Then switch back to autofocus, and see if it behaves.