2005 Buick Rendezvous Ultra Computer

Question: After a breaking and turning harshly on the road, to avoid a collision, my 2005 Buick Rendezvous Ultra's engine immediately stopped, and upon re-starting, all the dashboard lights and alarms, it seemed, began to flash and to indicate all sorts of trouble: Engine Needs service, Traction OFF, LOW FUEL (though the tank was full), Security, plus the odometer no longer shows any numbers, and worst of all, the fuel gauge no longer works. Also, the A/C no longer blows cold air, the seat position memory no longer works. It seems like a computer issue. Any ideas for a simple reset or fix? I understand this computer was replaced in the last two years. Thanks,
Santiago