Hi there,
Firstly, congrats on your personal achievement - that is no easy task! One does not hold an edge over the other. However, in general, there is a better chance a professional experience can be a better example for most candidates. When you pull on a personal experience, it isn't about the MAGNITUDE of the achievement. Rather, it's about what you LEARNED from it and took forward. Perhaps you were always driven or maybe the rest of your story says this in other ways. In which case, even though it takes a lot of effort to do what you did, you didn't learn anything new regardless of the results. However, perhaps doing this gave you the confidence that you could tackle any problem and so you dove headfirst into starting, for example, a non profit.
Do you see the difference between the two? The first is a perfectly fine essay with a good accomplishment. The second has insight and shows character beyond a single event. It shows how you grew and how that makes you a better applicant.
I hope that helps - if you have any questions, just let me know!
Bhavik