I always say to my H that I will fall to pieces when I lose him, I understand that incomparable and irreplacable bond of love and friendship within marriage that you describe. It's actually quite an unfair burden of me to put on him, he is significantly older and it's likely he will go first - he doesn't like to think of me falling to pieces without him (even though it'll probably be true).

It is in a way affirming to have and appreciate that bond, I am happy for you that you have that.

I don't know if it's relevent to you but in recent years I have nurtured and developed other friendships too, which gives H & I space and hopefully means it'll be less of a cliff drop for me when he's no longer here.