why does my car surge while driving and attempt to cut off when I stop?

Hello, I'm assuming auto-correct changed 'purge' valve to 'surge' valve in your problem description. The first thing that should be done is to inspect and test the EGR valve. When it sticks open while slowing to a stop, it can cause engine stalling. It is very common. If not the EGR valve, you may have a vacuum leak, or even dead spots in the throttle position sensor or throttle control motor (if equipped). Long story made short: test for vacuum leaks by spraying the engine all over with a fine mist of water. If the engine changes tune when you spray one particular spot/area, there is likely a vacuum leak. If no vacuum leak is found, you will need a good technician with Ford diagnostic software.