Something is broken. Short of sending both in to a repair center, the only way to determine if it is the camera or the lens that is broken (or maybe both are broken?) is to use another AF lens on the camera and to use the lens on another camera.
If you can't find someone else with a Nikon AF lens that you can borrow and/or with a Nikon camera to test your lens, there's not much you can do to determine which is at fault. If you're in an area where camera rentals are available, you could rent a lens and/or camera for a day or three to test your equipment.
It's highly doubtful you will be able to repair either yourself. AF lenses are easy to take apart. They're usually not so easy to reassemble properly with all of the optics aligned properly on a near microscopic scale without specialized test equipment and knowledge about what one is doing. There are also things inside that can be broken just by touching them with a your finger and getting skin oil on them or by transmitting micro amounts of static electricity.