White smoke and hard start

While sitting at stop light check engine light comes on and starts flashing, white smoke pouring from exhaust. Took it to AutoZone and came back with O2 sensor, spark plug/wire #6 cylinder misfire. I just changed plugs and wires a week ago, and the front bank O2 sensor a month ago. Did hard reset to delete code. No coolant in oil. Then this morning tried to start car and didn't want to start. Did a half revolution and locked up. Kept trying and finally started up but it made a hard knocking sound until it finally started. Engine was misfiring worse and a lot more white smoke. Once on the highway white smoke disappeared and misfiring was not so bad. Once at work the white smoke came back. Shut off car and checked oil and coolant again. Still no mixture. Decided to take #6 plug out and it was soaked with coolant. Guessing a head gasket. Tried to turn car over and starter made a whirring sound. Turned off car and took keys out of ignition and starter was still going. Had to remove battery cable for it to stop. Looked at the starter and noticed the bell housing on transmission is cracked where the starter bolts into. No fluid leaks. Need to know what to do.