If you have done all you can to make it work...if he has tried also, or if he won't even begin... then you have "permission" to leave... No one is required to stay in an abusive relationship.

Sometimes both know it needs to be done, and the discussion can take place calmly... you'll have to work together because of the children, so don't think separating will change everything.

What it might do, leaving, is show the children that they don't have to live with abuse. (You show them by example.) You might give them hope of finding someone to love them who is truly caring...when they are grown.

Sounds like there is no perfect answer here, but I wish you well however you decide.