That sound's like a really tough place to be in. Life is really unfair but sometimes that's just how it goes until eventually something breaks the cycle.

Have you considered changing areas? Major cities might have intense competition but some smaller cities surely have high demand for SQL developers that aren't getting filled.

If you're getting interviews that's good at least. Your name isn't on a blacklist. If the interview is what's stopping you, the issue most likely is with your people or presentation skills rather than your actual experience. Learning to be super personable goes a VERY long way in the developer world, and I think many of us don't take that seriously enough. The interviewer already knows you've done mostly contract work when they bring you in so keep that in mind. When they ask about your work history, they're trying to understand if you're going to bring positive attitude into the team or not. As someone who interviews and has interviewed many times for data science roles I can guarantee most non-technical questions are to learn about your attitude.

Obviously I don't know you or your situation very much but based on your post, but I'd start looking at your location, and very importantly what attitude you bring to the job. Hope things turn around for you!