Built a relocation tool that went viral (10K visitors day 1) - Need growth advice

What started as a late-night coding session during election night turned into something unexpected. I had this idea: create a simple tool to help people explore their options for moving abroad. Four hours of coding later, I launched a basic version. (https://whichcountrytomoveto.com/)
The response blew me away - 10,000 visitors in the first 24 hours. While the traffic naturally cooled down on day two, the consistent interest suggests I might be onto something here. I've been iterating on the tool since launch, adding improvements based on initial feedback.
Now I'm at a crossroads. My instinct is to double down on content creation, specifically well-researched guides about international relocation. But before I dive in, I'd love to hear from those who've been in similar situations.
Have you ever caught an unexpected wave of interest like this? What would you focus on to maintain momentum? All insights welcome!