Lost in Time - Backstory Struggles: "God, the Devil, and Divorce" Memoir Writing

This is the third version of my memoir: the first one was in the form of journals I kept over the last half of my twenty-five year marriage. The second version I wrote over a period of several years was strictly chronological and boring as heck to the few readers I shared it with. I'm determined that this third version will be the charm, and I'll tell you why it's so much more difficult to write than the first two versions.

In order to help the reader of the second version understand why I made certain life decisions, I began at the beginning of my adult life.

Talk about TMI; one editor described it as War and Peace! So this time around, I've started my Hero's Journey as I cling to my old life (my marriage) even while knowing in my heart of hearts it cannot endure much longer. But the reader needs to have some information about what got me to this point. That's where back story comes in, and that's where the ordering of events can get challenging. Here are some of the issues I encounter as I attempt to sustain my readers' interest and keep them from getting lost in time:​*Where exactly should each backstory go?
*How do I segue into backstory? Something present jogging my memory? Wondering why something has happened? Thinking how to tell someone something?
* Do I pick a subject such as my faith and show how it changed over time in one large back story segment, or do I dole it out in pieces.
*If I dole it out in pieces, do they have to be chronological? 
*Does each backstory segment allow the main thrust of the story to move forward? If not, how can I fix it?
*Will my readers be able to stay grounded in the present even while learning enough of the past to make sense of the present?
 
And so on. As you can see, writing good backstory is tricky. So I write and reorder. Cut and write. Until finally my story comes into focus in a coherent, compelling whole. That's my challenge.

Blessings,
Linda