I think that you did what you thought was best, and nothing should change that...you loved your husband, he died, he has gone on, and you have to live with that...rethinking what happened while he was dying, or where he was dying, is not good for you, at least that is my thought...
What is important, is that you did all that you could, the best that you could...
There are so many levels from the body breaking down vision, hearing, walking etc he really wanted to will him self gone!
So in a way I am thankful he did not suffer as Terri here they stop her water and food, at least he just slip away with comfort!