Why do A do this to us???
They don't. They just do it.
I was the one that allowed myself to be subjected to it. It's not your fault he hates his job - if it's that bad, he can find another one. Or go back to college and learn a new skill. Anything to get off his backside and work towards a better life for himself. Or, he can always choose to keep doing what he's always done. And you have the same choice, sweetie.
If you are worried that he is going to attempt suicide, call 911. If he's serious, then you've got that covered. If he's not, then he'll have some explaining to do and just might think twice about pulling that trick again.