Don't be too hard on yourself about having written a top notch article that is making you a nice income. It is impossible to predict which article and which topic hit that nerve with a wide readership and goes viral. Maybe it was a personal writing style that got you through to tens of thousands of readers, or maybe it was just the right moment to share and publish an article about weight loss. The point is, you are putting in your time, and, from what you are stating, you are writing and publishing consistently and sincerely. You've earned it, in every sense. It's good!