Let me suggest one technique for starting a personal essay. Remember that for a story to be powerful and memorable for the reader, it must be powerful and memorable for the writer. So sit back and go down memory lane and make of list of those memories which stand out for you. They could be good or horrible. List the top 5 or 6 or 7 of these. Now look over each. Is there one that stands out as something which changed you? Or strengthened you? Or tested you? If so, that is your topic, and a description of that moment/incident/scene will become the first paragraph of your personal statement. The essay itself will then be your transition to a stronger you, a changed you, a you who has overcome some issue, nemesis, flaw, or challenge.