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 :>