Aside from the other advice, I would also advise you to avoid the “How I Overcame Hardship” topic. It is cliché and overused, and more likely to cause an AO’s eyes to glaze over than to catch their interest.
Your story of stage fright tells me that you participate in some type of activity which requires you to be on stage. Tell of your experiences there, or of an experience you had as an independent teen. I am sure that you can find one which showcases your best qualities.
Good luck!