What do you do with a guy who just can't get it?

I've left my husband, for countless reasons, he's mean, out of work, smokes weed, just a terrible person and husband. Any way he did something unforgivable and it was the last straw. He seems to be acting like the victim though. "you guys are all I have" "way to time it when I'm down and out" I mean, he has no perception of reality and I think he's mentally ill. When he was home, he called me names, in front of our son, always mean to me, and now he's begging for forgiveness. I hate him, I don't even like him at all and I was just staying for my son, but now, that he did the unforgivable, I will never go back to him. How do I stop the harment from him.