Imminent unemployment, I have a screwed up CV; incompetent in my own field of PhD. Hoping for some perspective and advise?
Actually, I think that the way you did your doctorate implies that you can, in fact, learn the things you don't know now. In fact, you may have more skills than you realize, but I'll leave that aside. 

But first, the courses you took in the past are nearly irrelevant to the process of getting a job once you have a doctorate. The skills, yes, but not the courses. But few employers will feel the need to do any real examination of your coursework. 

I agree, however, that having some structure to learning is a big help. But you can address that in a variety of ways. Your alma mater might permit you to take some courses for a reasonable fee, especially if there is some service that you can supply to them in return. This might be an option if you do wind up unemployed for a bit. 

But there is now a world of online study possibilities. For many people they have little actual value, since the credential they come with might be suspect, but you don't need credentials at this point. But, if you do sign up for online instruction somewhere, be aware that just reading and watching videos isn't enough. You need to put the new information into practice so that it becomes actual knowledge. Use exercises for reinforcement and try to find a place that will also give you appropriate feedback on your work. Some online courses are better at this than others. 

So, I think that a two track plan would be worth pursuing. Work both in the job-seeking realm but also in filling in knowledge. 

If online courses don't appeal to you, but you have research skills, then there is no reason that you can't start on some project that requires the skills you don't have but can, as you did in your previous work, fill in via self study. If it results both in publications and in skill building all the better. Perhaps your old advisor can help point to some things, even if you are now remote.