1997 Opel Omega engine overheating

hi my car is overheating ,i was driving the other day to the mountain going uphill the temperature gauge start going up and then the gearbox stopped functitooning propely,so i stopped and i tried to cool the engine down ,i tried to take off again on drive but could hardly move,a messaget appear on the screen saying to check the automatik transmition,can u help me plz thanks