My car will not start and my key will not turn back

I would be thinking that the barrel and key is worn and locking up, if this is the case it will have to be replaced as an assembly, often this happen if key rings are over heavy with extra keys and trinkets, all that weight bouncing along while driving is doing damage to the lock, if you have to have extra keys try and keep it to a minimal to help avoid this problem.

Try to cycle the gear shifter from drive back to park and then work the key. If the key tumbler is worn out it could be jammed in which case it will need to be replaced. Here are some guides to help you see what needs to be done.

You will need to have the new key programmed to the car so it will disable the security system.

Please let us know what happens.

Cheers, Ken