If you're trying to make a living as a fiction writer, I certainly know a great many self-published writers who are able to do that. Literary writers, or even commercial writers like me, have a tougher time making a solid income from our fiction.
Now that many writers are turning to ghostwriting, since it has proved increasingly difficult to make a living due to publishing upheavals, celebrity-driven books, millions self-publishing books or writing for free, and Internet piracy, there is a new threat.
To be a published writer, you must tell yourself each day, over and over again, that novels are written one page at a time, or even one sentence at a time. If you're writing even a few sentences a day, you are a writer, and you will reach your goal.
Keep the back story sparse and sprinkle it throughout your book instead of front loading. That way, your narrative tension will be tight instead of slack, and your reader will be drawn forward by wanting to know the story behind the story.