I heard someone say something recently about their own loss which I found helpful. "You haven't lost a friend, you've gained a guardian angel". That hole in your heart does not leave and you can't fill it. It is a problem that no logic will solve. To say it should have been you is false logic applied to a situation that defies any logic. You are here, and that is what counts. I know that in my own grief I had to sort through all kinds of things people said to find those which were truly helpful and provided meaning to something I couldn't understand. My thoughts are with your aching heart for the pain you are feeling.