Keep. On. Improving.
Success is almost never instant. You should be prepared to find that you might need to work on and polish your project for a long time before people out there starts to understand its greatness. Of course, there is also a risk that they never will.
A recognized and much appreciated quality in any software is longevity. With age comes a proof that you know how to endure time and persist. That the project is maintained in a decent way and that after this amount of time no major disaster has been found.
With time, other people have also tested your project and there will be reviews and opinions about it online to find and learn from. Not everyone wants to be the first in line to try out a new project
Persistence is a golden virtue in Open Source. If you manage to hold out and keep working, fix the bugs and add the features people seem to want then chances are that your project finds its place and its users.
This is hardly any surprise to anyone, but projects in general tend to never really get finished and I imagine that Open Source projects in particular never do as long as there is a certain amount of users. There are always bug fixes to be made and people will always want to add more tweaks or features and then we get more bugs and repeat.
Projects typically finish when there are no more users (willing to work on it).
For individual authors and maintainers, the work on a project can of course end when they decide to just stop participating in that project.