What would be a good format for my personal essay?

So I know exactly what I want to write about in my personal essay. I am going to write about my first two years of high school and that I slacked off, wasn’t very motivated, didn’t work hard, assumed everything would be ok, 2.3 GPA during freshman year, and 1.9 GPA in my sophomore year (OUCH). But now I have a 4.0 GPA right now in my junior year, and now I intend on doing that again my senior year, I just became an Eagle Scout two months ago (which I think is a HUGE accomplishment and would help me BIG time in my college application), because I know what I want to be and what I want to do, and now I know how to get there and change my future for the better. I think this would be a very powerful essay but I don’t know how it should be formatted, organized, and written. Could somebody like give me a format template or can someone give me some suggestions? Thank you all for your time!