He has a problem that only he can solve. I would not stay with a man this unstable, especially as he has refused to get help. You do not have a problem with your marriage, you work and make "enough" money to suit you and clean and take care of yourself as well as you wish to and would like to help and partner with him but he will not let you.

Do not get a second job because he does not wish to work. You are working and are satisfied with your work and life; let him know his personal threats to you and refusal to work on your marriage is damaging that marriage and he needs to decide does he want to say in that marriage (and contribute positively to it) or does he want to drive you away. You cannot live his life for him, give him what he wants, only he can know/get what he wants for himself through his own living/life/personal work. You have your own life to live and it does not include carrying the weight of his illness or whatever when he will not try to help himself.