What's your financial standing? Are you doing this for fun and you already have enough assets to live on, or does this need to work financially?

If it needs to work, I think pausing development and focusing only on marketing, as you say, seems like a good path. And I'd try and do "high fidelity" marketing rather than low fidelity - e.g. approach people in person at the cafe at a gym or after their workout, rather than sending ads or emails into the void where you don't know what lands.

I'll note that it's kind of wild to have invested $1mm without a seemingly clear plan for distribution, but, it seems that you're taking steps to address that now at least.