The best college essays are based on experiences that have shaped you. You don't need to show your achievements – those are already in the Activities section of your application. Who's the person behind those achievements? What have you done that shows what people can count on you for in college and life?
Start by brainstorming your moments of growth and change. Write down as many as you can think of, and be as specific and detailed as possible about what happened in those moments! You can use that list to answer all your college admission essays – personal statements, supplements, and scholarship essays.