My advice to you, as someone with 20+ years in the industry:
Look at each job as a college course or internship you also happen to get paid for. Try to learn something new at your job every day. If you go several weeks without learning anything new, start looking for another job. Even if you're only a few months into your current one, doesn't matter. The job market is great, and you can spin it in a positive way. I've been asked about it in interviews, and my answer is that I work hard to make a positive impact every day I work somewhere, and to ensure that even if I work somewhere just one day, they are glad to have hired me.
While you're doing this, start looking for a problem that you want to solve. This is typically born out of your own pain point, or someone close to you. Start working on it, and looking for a way to solve it in a way that is beneficial to you. Typically, this means providing support for your software in return for something else, either money or barter.
Do not allow yourself to invest emotionally into your money work, because, as you have seen above, it is disappointing. Remember the college course strategy above, and don't allow yourself to be upset by work bullshit.
While you're doing all this, minimize your lifestyle expenses and save your money. This will provide you with runway when you're ready to lift off your startup, while at the same time extending the length of runway each dollar provides.
Good luck! Based on how you described yourself, I believe without a doubt you have what it takes to achieve happiness in this field.
BTW, I noticed your other post about textfile-driven development, and I am working on just such a project. I use SQLite for an accessible index, but I insist on human-readable text for both config and data for the base. You can learn more about it via my profile.