Q: Cant keep coolant in tank no leak on ground no coolant in oil overheating hest blows cold changed t stat and cts multiple misfire

All of a sudden Saturday my car overheated on the mail route while reversing from driveway. Coolant tank was overly full and boiling and I was able to squeeze hoses. Hot air in was not blowing hot. My fans stayed on for 15 minutes or so which caused my battery to die. I was jumpstarted and drove home to let the engine cool down. Once cooled the coolant tank went back to normal level and I was not able to squeeze hoses. I continued my route for an hour and a half with the heat running when stopped at a mailbox watched the heat gauge rise to the red and turned the car off. Again fan stayed on and killed battery. Sunday we changed the thermostat and oil. And added more antifreeze.overheated rather quickly on short drive again coolant tank was empty and there is none on the ground. Changed the CTS and A day later the check engine light came on code read of #2misfire multiple misfires. White smoke from exhaust. Changing spark plugs and wires. Please tell me notnhead gasket_!?!?!

My car has 160000 miles.
My car has an automatic transmission.