Google Play Store Error Even After Factory Reset

After updating latest KitKat version 4.4.3 I got this Google play store stopping error and after followed n number of steps and instructions finally even I factory reset ed my nexus 5 and due to my small mistake which I forced Google play store in installation I am suffering a lot now ,even after factory reset Google play store is not present in my phone so again I installed from apk then again problem starts as like day one.

Any steps still balance to follow and I donno about rooting.