I tried to turn it off the key was jammed

I recently came back from a long trip and put in a key in my 1993 Chevy S-10 Blazer and jump started it. Well when I tried to turn it off the key was jammed and it would not go to the lock position. There is now lever like some models. It will not move toward the lock positon. My wheel moves freely and the ignition alignment point is about 3/4 of an inch from the lock position. Bottom line is I can't turn the key down to turn the vehicle off. Today I took the cotter key(pin) off and removed the bolt to remove the steering wheel. Any advice would be helpful. I purchased the book today so I could work on the brakes; however, the ignition...(key jam) was not in the book at all. Thanks in advance for any reply.