You cannot prevent him losing his job--he's an alcoholic. He WILL lose his job eventually, that's a damn near guaranteed fact. Whether it's because he's sleeping there, his court case, drinking on the job, or something else, alcoholics generally lose jobs. It's part of the alcoholism. (I know there are exceptions, but not many.)
So, rather than trying to rescue him from his poor decisions, I would suggest putting all your energy into finding another way to support yourself and your children. Because, no matter what you do, it's unlikely you will be able to count on him for financial support. He's an alcoholic.......
L