Trust me on this one...I think you have a bad cylinder. I have been through this on two cars and your symptoms sound just like mine. If you can't get the key to turn one more time, you are looking at some real fun. The ignition switch assembly is "T" shaped. The long leg of the "T" engages the steering column. The top of the "T" has an electrical connector on the back the and cylinder on the front. The long leg has a clamp around it where it slides into the steering column. There is one bolt that cinches it down tight. You will need to remove this bolt. Under the clamp, there is a small pin that you will not be able to depress as you can't turn your key. If you can get a dremel tool in there, you can cut it down so you can slide the entire assembly out of the steering column. Once the assembly is out of the car, smack the heck out of it with a hammer and you might free it up one last time so you can get the cylinder out. Hope to God you can or you are in for even more fun. I speak from experience in all of the above. Get yourself a new cyliner and key and you should be back in business. If you can't get the lock to let loose, the only way to get the electrical connector off of the back of the locking assembly is to cut it off...if memory serves me. Hope some of this helps. It is not a fun task, but can be done.