1995 Chevrolet Blazer Good Evening Ignition Key Did Want Turn Starter After

Good evening. The ignition key did not want to turn to the starter, then after the engine cranked up did not want to turn on the off position. After many temptatives I was able to shut down the engine, but when I put the key on the start (when the dashboard lights start on before to move to the next position to turn the engine on) wont turn on the lock position anymore, I can only go far like to start up the engine again. The key is stuck. What can be the problem? Bad cylinder key? Someone said ignition switch...
Thank you for your eventually help.