lack of motivation

I want to write a book. I actually started writing it. Three years ago. I'm still only on the ninth page of a book [well, two books] that is to cover almost seven years. It might need a little more work. And as usual, I can not bring myself to work on it. I should. I find different reasons not to. Primarily the "I don't have time" exuse is quite high on my list, followed closely by the "I can't think of a fake name to replace real names" in my semi-true, based on my personal experiences in retail story. And of course there will always be the "don't want to dig up those past demons that are so interlaced with the experiences in the story" arguement.
How does one take a true story and pick apart the portions that one wants to tell while ignoring the ones that you dont want to share when one relies heavily on the other? How do you relive the painful parts of your life, while currently dealing with new painful experiences? I believe that if I am happy, maybe I can look back and see those event as what they are, growing pains. But if I am not in the place I want to me, looking back only reminds me of my failures, past and present.
Above all, for all my grandiose facide, I don't think very highly of my abilities. I know I have a book in me, yerning to fall like rain onto the pages of a novel. I wrote my first story in first grade. Attempted my first book at age 12 (a childs guide to coping with your parents divorce), my second at age 15 (a horror story from the view point of a divorced mom - which is still 5 pages further than I have gotten on the current book), and now this one.