I really believe people leave a footprint on the lives they've touched while alive. It's a part of us that stays long after we have left.
Reading your post it struck me what a strong footprint your husband left in those last months and what a treasure they are to you. In a sense he left behind a deep understanding of what you see in others. Maybe allow yourself to feel the power of good it was each time you understand and see it in another.
Maybe his will left that footprint with you to give you a smile when you remember and see it in others around you, even though he was ill and would die.
But this is just a guess from what you've written - you'd know better than me if there's truth in it.