Key Won't Turn in Ignition

I have a 2001 Malibu. I can put the key into the ignition but the key won't turn. It won't move past the off position. My steering wheel isn't locked and won't lock no matter how I turn It. The gear shift is in the park position and won't shift into any other gear. The break also seems to be much harder to push than normal. I have no idea what is causing this. I recently disconnected the ac panel from the dash to repair the a/c button because it was sticking. After repairing it I started having the problem with the ignition. Any idea what it could be? I do have a security system that came on the car. Maybe that's causing it? Any information would be greatly appreciated.