Where is the line drawn?

I'm 23. I have three kids, and my husband is getting worse.

He is from a sketchy background. Low socioeconomic, drugs involved. And some form of domestic violence. Mental, very threatening. He never talks about it. So I'm not sure. He says he never realised it wasn't normal to not have food to eat, or be frequently kicked out of home.

I grew up the opposite. Middle class, very emotionless upbringing. High morals.

More and more, my husband is loosing it. I'm treading lightly. Afraid to do anything. He breaks things, and looses it out of no where. He has flipped tables, smashed a tv, torn apart an outside wall, broken appliances, thrown a broken ipod in my face...

I saw one in our first year of marriage. Nothing in dating. I cried and he stopped.

Two in the next year. One my best friend was there for, but it didn't stop him.

This year, it feels like it has become every four months.

It's like he's posessed when he's angry. He treats me nicely enough otherwise. Bit of a selfish prick, but honestly, I haven't met a man who isn't. I feel creeped out. Like I am standing before a monster. It takes days, weeks... before that awful dark feeling seems to ebb and I feel a bit more like I can be normal.

My friend, who wittnessed it, recently sent me a post of what defines d.v. and it fit.

So.

What do I do now? :/

Can I call the police for help next time? Should I leave him? Threaten to devorice if he doesn't get councilling?