Either way, this jump is disturbing, but the description likely caused you to cringe more than the summary. And doesn't some part of you want to know what happened next? Who came to help? How quickly they reached a doctor? If all had turned out well in the jump, you would not have the same compulsion to read on. If you can't think of any details, write a line of summary and return to fill in the details as you remember them. If you remain relaxed about it, you will remember. If you don't, you don't. Writing an autobiography isn't easy, but it should be enjoyable.
"I was 12 years old when my mother passed away. By the time I was 15, I had become an expert in dodging bill collectors, recycling hand-me-down jeans, and stretching a single meal’s worth of ground beef into two family dinners. Although I was a child when I lost my mother, I was never able to mourn or to let myself become too absorbed in thoughts of personal loss. The fortitude I developed at a young age was the driving force that would see me through many other challenges."
Develop a central theme, main idea or thesis that clearly explains the purpose behind your autobiography. For example, your theme might be about how you overcame obstacles to become a stronger person, or it might explain why a particular passion -- such as mountain climbing or rescuing animals -- is so important to you. Back your theme with details and background information about your life experiences. For example, you might explain that your dad is in the military, so you've had to learn how to adapt quickly to new schools and unfamiliar environments. Or, you might discuss what it was like growing up in a poor, single-parent home, but how your family was always willing to take in injured or stray pets.