Yes, it feels almost impossible because accepting she is gone and moving on cannot live in the same space as wanting to save the marriage.
I wholeheartedly, 100% disagree with this sentiment.
The way I see it, you need to live your life as if she is not going to 'come around'. Part of that means accepting that the relationship is over.
That does not at all mean that you need to stop wanting to save your marriage. What if I told you that doing ^^^ IS the best way to save your marriage?