This is the same wall everyone runs into: product market fit - chances are very good you'd encounter this issue on Envato's marketplace if you published something unknown today too.

There's no easy answer, you can optimize around getting traffic from sites like ProductHunt, HN and Reddit but these sites can't elevate everybody and rarely have much impact.

You can find people to blog about your product but it'll take a long time to snowball into something.

You can find WP dev or user communities to infiltrate but they also have more people selling than buying, many will be wary of newcomers with something to sell.

You can find freelance sites and try and get them to promote your product to their clients.

You can advertise and try to balance your ad spend against your revenue successfully.

Probably the most effective thing you can do is go back to Envato where you say your success was "almost entirely on autopilot" and see what happens if you put some effort in and build on that success instead. You might be able to double or triple your revenue there while pursuing the slower strategies of driving traffic to your SaaS.