'04 CTS. Bad ECM?
 

2004 CTS 3.6L 130K
Was running fine until last night. I crank it up after 3 hours of sitting.
First thing i noticed was the orange marker on the gear shifter didn't come up. About 2 minutes down the road, a message saying "service theft system" came on.
Next was the security and traction control lights. 7 minutes later, everything in the cabin went black. Gauges, radio, window and lock buttons, even the air stopped blowing cold.
I got to my destination in another 7-9 minutes, turned it off, and the key was stuck (wouldn't fully turn.)
Checked fuses. Battery isn't even 3 weeks old. Everything seemed okay. Undone the battery and left it overnight.
Reconnected this morning and everything worked except for the fuel and temperature gauges.
Went ahead and drove the 15 miles home, but a little over half way everything went out again.
SOMEONE HELP ME, PLEASE! 😭