Hi @Lostandalone
It sounds like youve been having it rough. I've been there many a time. I've ended up in several jobs that weren't the right fit for me. I can only shed light on what I did.
These jobs caused burn out and the inevitable decline of my mental health. I left after the breaking point. If I could do it differently, I would have left earlier. Jobs, while difficult to come by (particularly in my industry) really are not worth the pain once you reach breaking point. Ive learnt that in life, it's important to know what you don't want to do, as much as knowing what you do want to do. And if it comes to an environment that isn't helping you develop yourself, career wise as well character wise, then the only thing tying you to a job is income. And it's better off gaining that elsewhere with less stress involved.
Although, I know circumstances are hard now with covid 19 and employment. I imagine there has been a sit down with your employer discussing constructive feedback regarding your performance? Is there any way that you can work on these points at all? Perhaps them firing you isn't actually on the table. We all stumble with our work performance and we all can learn and take it as an opportunity for development.