One of the ways I think of it is by imagining that every bit of information you have taken in from birth is a book in your own personal library of life. Every time you acquire new knowledge, new perspectives, new relationships, new faith, etc. you get a new book to put on the shelf as you go. (A bit like the memory balls in the movie Inside Out). Well, losing a child is like taking all those carefully placed books and dumping them ALL into an enormous heap on the floor.
I was amazed at how the death of a child uproots even some of the basic beliefs that you operate your systems of existence around. My world was an orderly place. You work hard for what you want and that’s exactly what you get. Bad things happen to other people. Death is an orderly event that happens to old people who are ready to go or to other people. By being good and seeking God, somehow the cosmos will give you only the good things you deserve. 
On an intellectual level, I knew that wasn’t how it really worked, but in my own little bubble that’s how it had always gone and I hadn’t had any major experiences that forced me to bring what I knew intellectually to the level of my heart.
Then Lachlan died. My physical shelf still stood, but everything that was inside the shelf was now in a heap on the floor. I had to re-shelf and re-organize all of my books. I had to find a way to allow “The Death of a Child” to coexist in a universe with an “All-Loving and All-Good God”. There had to be a place for “Terrible Tragedies” to fit next to “The Things that Happen to Good People”. “Good Deeds” didn’t belong with the book about “deserving” anything different than anyone else—in fact, that book had to be removed completely. I had to find a place to keep the idea that I would have to live this life without the physical presence of my son…you get the idea. Where does my identity as “mother” belong when one of my children no longer walks the planet? Now I knew in a whole new way that there were no guarantees in life…my old organization system didn’t really work that way.
The job of putting the “books” back on the shelf is enormous and overwhelming. You can’t scoop them up in heaps and shove them back into the shelves and expect to have a functional system. You are really forced to pick up and evaluate every book one by one. Does this book still belong on my shelf? Can it fit in its old position? Does it need a new place? Where does this belong? Here’s a new book I’ve never seen before…where does that go?
The pain and chaos that comes with the loss of a child cannot be healed quickly. It is reconstructing and reorganizing life’s entire library of thought and experience one single book at a time. At times it may be with shaky hands and overwhelming uncertainty, at others it will come more easily. In one wobbly baby step at a time, with time and attention to the work, healing will come and a new and functional system can be established.