You know the answer to your problem. Get in dash gizmo system repair or change if its gone bad. Btw its not car computer, thats ECU that controls your whole car not just AC and Music.
However try disconnecting battery terminal for an hour or so and then restart the car, it might reset to factory settings if its jammed internally due to some bug (just guessing). Hope it helps.
Check all the spark plugs, wire and there firing order.
If not get your fuel pump checked (in last). It may have worn out O ring (rubber) that holds pressure and supply fuel with pressure.