If you ever find yourself in a situation like that again I would recommend calling the police.
You didn't cause this, You can't control it, you can't cure it.
You can't make him get help - he has to do that himself and he has to want to.
There are some great stickies with tons of information and help here. At this stage I would advise finding out all you can. There are many wonderful people here who will support you through this horrendously difficult time.
Welcome to SR. I think you have come to the right place.