2003 Volkswagen Jetta Question: I have a 03 vw jetta 2.0 the car has had problems starting.

the car runs hard like the engine is going to jump out terrible at startup and it seems like it is not getting gas.I had a diagnostic done and they told me i needed a crank shaft sensor temperature sensor o2 sensor and possibly a thermostat. i have changed everything except the o2 sensor car still runs terrible and sometimes it will not start. I have replace spark plugs wires and iginition coil timing belt serpentine belt all within the last year. I am at 147,000 miles.