I'm pretty discouraged, I'm 37 and I've tried numerous attempts over the last 20 years to start a software business as a solo founder and none have worked. I've been working part-time to cover the bills while I work on creating the software I hoped to turn into business. My wife and I plan to start a family in the next two years, and I need to start getting serious here for my family's future. The industry is really hot right now, and I can make great money if I just get a full-time job.
I'm building a programmable PostgreSQL proxy in Rust. The idea is to make it easy to consume the replication stream so it can do query caching with automatic invalidation, and so that people can build custom partitioning, caching, or real-time features on top of PostgreSQL. The proxy part is implemented, but there's still a lot of work to add the replication and caching features, and to test and polish everything to production standards - databases are serious business. The project is on github here: https://github.com/riverdb/riverdb
I don't even know if this is something people would want or pay for if I completed it. And then there's the task of marketing/selling it, which is way outside of my skillset.
Should I just give up (grow up?) and get a job? Is it worth pressing on here? I'm not consuming my savings, but neither am I making financial progress, and I'm not getting any younger.
The description of what you are building sounds like a deeply technical, profoundly specific thingie for deeply technical people (with unknown market, and unknown business proposition at best). The fact you have not started with or outlined the problem it solves, the business need, or who is the customer in non-technical terms feels like a massive red flag to my naive mind. Bluntly, at best it sounds like a "tinkering hobby" - NOTHING wrong with that, unless you need to pay the bills :).
I would suggest getting a job in a place / position where you can observe the business flow, verbiage, get some mentorship, and not only pay the bills, but set yourself up for long term success should you desire to build something of your own again. I have no idea what your technical prowess is, but it sounds like you may have spent your years building stuff rather than building business, and that's where your growth opportunity lies. To put it another way "Selling and marketing are not my skillset" is almost a token of pride for us techies, but it is empathically not a successful mindset for a potential business owner. If marketing and selling are of no interest to you, and you just want to do the technical part, than accept your own preferences and priorities and go work with/for somebody who does prioritize and excel at sales and marketing :)
(all this of course based on reading three paragraphs you've shared and therefore as likely completely misread and wrong as not :).
Best of luck!
P.S. For what it's worth: nothing prepares and nobody can explain to you the MASSIVE transformation and upheaval of your life that having children will be:). If money is in any way a stressor, to you or relationship, or if this brings you anxiety, that's another good reason to settle that down before kids come along :>