You need to spend a lot of time thinking about your product and who actually wants to pay for it. Who are your ideal customers? What are their challenges? How does your product solve those challenges? How high a priority are those challenges to that audience? Is there an audience that would put them at a higher priority? How much is it worth to them to solve those challenges - how are those challenges currently affecting their business and how much money could they make / save if they fixed them?
If you figure out these answers and get to know your targeted audience very well, you will then understand how they learn about new products and evaluate them. You can then start marketing to them in their language with the value proposition of how your product solves their problems. Put ads up where they will find them, hang out in forums and chat rooms and such where they ask questions, write blog posts about things they are interested in and make sure they get picked up by search engines and - hopefully - news aggregators like this one where your target audience is reading. It's a slow, iterative process that keeps building on itself as you keep going and building momentum. It will be very discouraging at times, but you need to really understand your customers and, when you do, you should be able to figure out why things aren't working when they aren't and how to fix them.
Don't worry about going big and scaling - make enough money to support your needs (and trim your needs as low as you can while remaining comfortable). I found consulting clients by posting on my LinkedIn feed. I have one major privilege here - I've been in the industry for more than 20 years and have built a sizable network as a result, all of whom were eager to help me find clients. The bulk of this network is only a few years old, though, so there's no reason you can't build a similar network yourself, if you haven't already.
As technologists, we tend to focus on the tech. Spend some time focusing on people, their problems, and how you can uniquely solve them - better, faster, more focused, whatever. You may even find tech isn't the answer to solve for - it may be education or writing or running workshops or something else.
And, mostly, build trust in yourself. All of this stuff seems so complicated at first, but that's because we complicate it needlessly. You want o be successful in business? Find an audience that has a need, really understand the consequences of that need and what it means to that audience, create a solution and solicit feedback from the audience, then sell to those who respond favorably. Then, keep listening to them and intelligently improving it to grow the business. If you sit down and think about how YOU would go about doing it, you may find most of the answers you're looking for.