engine and sputtering problem

Jerking when you put it in reverse could be due to bad motor mounts, especially the top front 2 motor mounts, but they are easy to change out. The high idle and engine dying could be an issue with the throttle, IAC (Idle Air Control) valve, or a vacuum leak from a hose or intake gasket. You might have a bad fuel pump resistor if there is low fuel pressure at low rpm.

It's jerking because the engine is idling way too high to switch into gear. Try not to shift it untill you get the RPM back down to 1200 or less, don't push the tranny. What was the car doing before the new parts were installed? Does it smell like it is flooding? Try starting it briefly and check the exhaust. I need to know if your running rich or lean to get closer to the problem.