Car is locked up

I have a 96 Pontiac Sunfire. I'm having trouble starting my car. When I put my key in it. Its jammed n won't allow me to turn it. I tryed rocking the stearing wheel back n forth but that' won't bug at all. I checked to see if my car was fully in park/tried switching gears back that remains in park. I even tried pushing the car back n forth but nothing. Is there any ideas on what the possible problem is. Please let me know. I'm thinking it has to do with the ignition switch.