At this point, I'm fairly convinced that I'm a complete idiot, but now it's too late for me to change my career trajectory. That is, I need to publish in order to hold my current job (that of an assistant professor). I'm honestly clueless about how to accomplish that.
Firstly, this sounds to me as a classical case of an Imposter syndrome, which is rather common in academia, where smart people are constantly in contact with many other smart or even smarter people. I am not going to play a psychologist to you, but you can read more about this and find easy proofs that your current position probably proves that you are far from being an "idiot".
On the other hand, sober evaluation of your perspectives and predispositions for academic career is in order. People do quit academia and find happy life, do outstanding contributions to science, and even return to academia at much higher level. All this is not visible, if you have spent all your life in Universities, talking to other people who have spent their lives in academia.
However, I would warn against thinking that getting a job in industry is a walk in a park, paved by dollars - it actually may turn to be quite a struggle, not easier than the struggles for positions, grants and awards in academia.
However, what might be easier for you personally, is that "in the open" your advancement would be less dependent on your communication abilities: finding collaborators, making friends with important people and grant managers, etc. (Provided that your communication abilities are good enough to answer questions in a job interview, avoid insulting your co-workers, etc.)
The problem is that I'm not smart enough to solve research-level problems on my own, and therefore I need collaborations to be able to publish anything. Now you could argue that I didn't belong in academia, and I'd wholeheartedly agree, except that it's too late for me to go do something else. (Let's just say, visa issues are also involved, in addition to my advanced age.)
It is never late to explore other opportunities, especially if the failure of your plan A seems more and more certain. Also, returning to your home country might be not as bad as you think after being away for several years - sure, life is not everywhere as comfortable and easy as in North America or Western Europe, but it is quite bearable in most places (and if it is really unbearable, then applying for a refugee status should be in the cards.) You may also consider going to a third country and relaunching your career elsewhere, perhaps in a less prestigious institution, but still...