If the project becomes too much for you at any point, remember that writing an autobiography takes time. Take the pressure off. Relax. This is your autobiography. You can make it as brief or as complete as you like, but don't expect to write it quickly. It may take years. If you want to finish fast, you might try the $14.95 Memorygrabber software I mentioned early. The publisher offers numerous free downloadable pages on their website, so you can decide if that approach will be useful or not.
Why it helps: Sometimes we avoid the most obvious—and complicated—events that have happened to us, events that inform our whole life story. Let’s say your three-sentence exercise was Loving mom who worked all the time, no dad. Never really got over lonely childhood. Maybe you could try, “I was just a kid but...” or “I tried my best but...” Was there something else that happened that prevented you from getting over your lonely childhood? Did it happen when you were a child—or later? Did it involve parents? You don’t have to know the answers to these questions. Let the pre-written prompts guide you. “Don’t think and write,” says Temes. “Just write.”
Use chapter divisions to give the book structure. Chapters are useful because they allow you to move on from discussing certain life periods or events. There's a reason we have the expression that we've "closed a chapter" or "opened a new chapter" in life, and it's even more applicable when discussing an autobiography. Chapter breaks allow you to skip forward 10 years, go back in time, or start describing a new theme without jarring the reader too much.
I think the first and best step to getting things out – but not necessarily writing your life story for anyone else to read – is to buy a journal. Start writing about your experiences and painful memories. It will hurt, but the only to get past the pain is to go through it. The more it hurts, the better it will be in the long run to process the experience.