The source that told you to shoot to stop was correct. Shooting to stop does not imply attempting to "wing" the attacker. Shooting to stop means shooting at the center of the vital area, until the attacker stops his violent activity. If he's dead, dying, or maimed, too bad. The point is YOU stopped using deadly force at the point he was no longer a threat.
It's a fact of life, if he lives, you will most likely be sued in civil court. Demonstrating that you know, and correctly applied the laws regarding use of deadly force is your best defense in that situation.
If you keep a gun for self defense, you need to accept that using it for that purpose WILL change your life as you know it (and not in a positve way.)
Weigh that againt not using it, and changing the lives of your loved ones in just as dramatic a way, when you are yanked out of their lives.
"Shooting to kill" would imply walking over to the downed, but still living, former attacker and popping two more in his head. That makes you the aggresor and guilty of using excessive force, if not outright murder.
To add to Aimless' comments on what to say to Police I would add:
That man attacked me (Cops only see victims and perps, you MUST claim the mantle of victim despite the bloody mess you've left lying in the hall)
I was in fear of my life, he had (insert a means of inflicting death, or grave bodily harm)and he was atempting to hit/shoot/cut me with it. (To legally use deadly force, the attacker must have the means and intent to cause grave bodily harm or death.)
This person, that person, and that person there were witnesses. (if appliciable. If there are witnesses they will be interviewed anyway. It won't hurt for you to identify those you know saw what transpired.)
Officer, you know how serious this is. I will continue to cooperate with you, but would like to have my lawyer present before saying anymore.
I'd then get a lawyer, and have them hire Mas Ayoob as an expert witness. He can point you to lawyers that have defended self-defense shooting cases.
Let's face it. Most lawyers only have experince getting guilty people off and will not know how to handle you standing up in court saying :I shot him, and under the same circumstances, I'd shoot him again."
Most Lawyers have far more experience using the SODDI/TODDI defenses that are not open to you having survived a self defense shooting.