If you can't find the job you think you should have now, it could be luck, or it could be that there is something important you don't understand. If it is luck, then its a numbers game, and you just need to try enough times/for long enough.
The thing is, it sounds like you've been trying for 6 months. If your problem was luck, that would seem to be enough time to have at least come close to getting what you consider to be a suitable job. So, more likely, then, that there is something important you don't understand.
One way to figure that out is to keep at it, but if you haven't figured it out by now, why will things be different in 6 months?
Another option is to try something new/different. In some ways, it doesn't really matter what, as long as its new/different, because that will inevitably lead to you learning things you don't know now, which will shift your perspective in ways you can't predict now.
So, what to do? Well, plenty of options, but a paying job that is related to your training and interests sounds perfect, for the time being. No telling where it could lead. Dive in, do your best, learn everything you can. Unless its a truly horrible fit, you should be able to get at least 6 months out of the novelty. At that point, you'll either have a pretty good idea if it is somewhere you want to stay for a while, in which case your path should be fairly clear. At 6 months, if you are ambivalent, or you are sure you don't want to stay, you can/should start looking for a new job. It will take a little while to gear up, a little while to get interviews, a little while to get job offers. By the time you'll be ready to start a new job, you'll probably be close to 1 year at your first job.
The biggest mistake is always spending too long doing the same damn thing, whether that's looking for the "right" job, or muddling along in something that isn't the right job (often because you are spending too long looking for the "right" job). When in doubt, different is better.