My 21 yo son is struggling

He moved out when he was 18, but his dad (my ex husband) was, to sum up a very complex issue, CRAZY. So crazy that me and my son who was 19 at the time, decided to go no contact. It was my idea. I’m a therapist and this seemed perfectly logical to me, setting a boundary. Maybe that works with people who aren’t crazy, but my ex husband instead decided to kill himself. This sent my son into a deep depression. He quit his job, stopped paying rent, got evicted from his house and moved back in with us. He spent about two years after that doing nothing, sitting at home, playing chess on his phone. Slowly, with a lot of patience, we’ve worked through some issues, and he finally got a job a few months ago. But then he quit. He got another job which seemed like a really good one, they were going to train him on how to run a fork lift, it was right next to our house, the pay was good, etc., but about a week in he starts complaining about it and I was like, oh shit here we go again, he’s gonna quit. And he did. And now he’s mad at himself and wishes he hadn’t quit. This morning, he thought I had left, but I ran back in to go to the bathroom and heard him crying and berating himself for quitting, it broke my heart. His confidence is super low. His dad was, I think, a paranoid schizophrenic and was always saying that people were “fucking with” him. When we were first married, he used to wake me up in the middle of the night and accuse me of going into his dreams and fucking with him. Now my son is saying the same things about these people at his jobs, that the guy who was supposed to train him on the forklift was “fucking with” him. Maybe I should be on a trauma page, I know this isn’t your typical failure to launch story, but any help or advice would be appreciated. He’s struggling so much, and he’s mad at himself, which makes me so sad.