I'm sure others will chime in before this is over, but two things come
to mind.

1.  What is called "Vanagon Syndrome".  That's where the wiper in the
AFM is moving rapidly back and forth in essentially the same place (long
time driving at the same speed) and it confuses the ECU.  One trick is
to remove the AFM cover and carefully clean the wiper surface.  If it's
worn through, the Phillips screws that hold the board down can be
removed, the holes in the board elongated, and put back so the wiper has
a new surface to ride on.

2.  An ignition switch (electrical portion) that is cracked or going
bad.  It's not unusual for them to fail in such a way that turning the
key to the start position "Opens" the contacts for regular ignition.
That fact that yours started easily by push starting it points to this.

Mike