I do understand how do you feel. I quit my PhD, it was crazy.
Then the life was better, having normal jobs. Now I have another very difficult situation in life and there is no chance to get professional help. At least some friends are helping.
If you are from south Germany, let me know, we can grab a beer and talk. The life will be better again!
Not sure if it would help, but if you're around the Berlin area and want to grab a beer or coffee with another guy that left academia for the industry (and still has delusions that someday will submit his thesis), hit me up.
Isolation is a real problem in this country. Did you also make the mistake of moving to a small city? I spent my last four years at a TU in a small city and it was horrible here. Just one more general problem with this country.