P0444, P0492, P0491 Fault Codes - 2002 VW Passat AWD 2.8L Diagnosis and Repair Guide

My 2002 VW Passat AWD with a 2.8L engine has been running fine until today. After refueling and parking to run inside for a drink, the car failed to start. I had it towed home and connected my OBD2 scanner, which revealed three diagnostic trouble codes: P0444, P0492, and P0491. As someone with no mechanical background, I researched these codes online and began troubleshooting by inspecting the evaporative (EVAP) purge control valve. During inspection, I discovered that the wiring harness connected to the valve was disconnected. After reconnecting it, the car started but exhibited severe roughness—shaking violently—and failed to accelerate when the gas pedal was pressed. Pushing the accelerator resulted in no response, and the engine would eventually stall. I tried adding more fuel, but the symptoms persisted: shaking, lack of acceleration, and sudden stalling. I am not experienced with vehicles and have no idea what the next steps should be. These codes suggest issues related to the EVAP system and possibly the fuel delivery or engine management. I need clear guidance on how to proceed—especially since P0444 (EVAP System Purge Control Valve Malfunction), P0492 (Evaporative Emission System Leak Detected), and P0491 (Evaporative Emission System Pressure Too Low) point to a system-wide issue. Any help or advice on diagnosing or repairing this would be greatly appreciated.