This is a very, very common failure mode of new entrepreneurs. As long as you don't have any customers, any promises, or any deadlines, you can focus on the best part of being a programmer: programming. Thus people often end up postponing the customer acquisition farther and farther into the future, until they run out of savings, or just abandon the project because the bright flame of new creation has dwindled.
Running a software business sucks. You have to mete out your attention extremely carefully, and without well-vetted potential customers to build things for, building things should be very low on your priority scale.
You can achieve most of your stated MVP goals with a sketch made in Adobe XD, with a fraction of the time spent.