An abusive man has already abandoned his family. If he has abandoned providing for his household he is worse than an unbeliever per 1 Timothy 5:8.
But if anyone does not provide for his own, and especially for those of his household, he has denied the faith and is worse than an unbeliever.
1 TIMOTHY 5:8 NASB
This is a sin that is unto death, which does not mean he can't repent or be drawn back to repentance by the Lord, but that as Paul out it in his letter to Corinth. In 1 corithinans 5:5 Paul says to hand a man over to Satan for the destruction of his flesh, so that God can save his soul. I know this man isn't abusing his family in the same way, but he is having an affair with his fathers wife, which is a whole other can of worms. However I say this because your husband has abandoned his family in his abuses, and does not provide for them in his neglect. Now according to scripture he is worse than an unbeliever (worse than) according to scripture. Being engaged in behavior that categorically makes you worse than an unbeliever is likely what John means by sin unto death in this passage;
If anyone sees his brother committing a sin not leading to death, he shall ask and God will for him give life to those who commit sin not leading to death. There is a sin leading to death; I do not say that he should make request for this.
1 JOHN 5:16 NASB
Which I would say is comparatively similar to the situation in which Paul says put this man out so Satan can destroy his flesh; but this is not necessarily the end for this guy because Paul adds that God may save his soul. And indeed later you find in the second letter to the Corinthians, Paul says to accept the man back into the fellowship;
But if any has caused sorrow, he has caused sorrow not to me, but in some degree—in order not to say too much—to all of you. Sufficient for such a one is this punishment which was inflicted by the majority, so that on the contrary you should rather forgive and comfort him, otherwise such a one might be overwhelmed by excessive sorrow. Wherefore I urge you to reaffirm your love for him. For to this end also I wrote, so that I might put you to the test, whether you are obedient in all things. But one whom you forgive anything, I forgive also; for indeed what I have forgiven, if I have forgiven anything, I did it for your sakes in the presence of Christ, so that no advantage would be taken of us by Satan, for we are not ignorant of his schemes.
2 CORINTHIANS 2:5-11 NASB
So with out the action taken in 1corinthians the reconciliation of 2 Corinthians isn't possible.
Ok to my point.
He is in the place of one who is worse than an infidel, and must be put out for a time until he repents. This is his only hope.
As for you, what you can do is pray that his sin is ever before him. That the holy spirit convict him day and night for his sins until he breaks under the load of his sin and convinces him of his need for Christ so that he repents. And for you that the spirit of the Lord be your strength and wisdom and comfort that will continually seek an intimate relationship with Christ.
I hope that I am clear and that it is helpful. If not I do apologise.