I totally agree with Elaine. As she said, it's easy to say leave and this isn't right - but you are responsible to protect your child as a parent - that's YOUR JOB! And - I'm speaking for mothers here.
If you put your child in danger and something happens to them, you will have your child taken by social services - worst case scenerio. So, do not let it get to that point. You will feel better, believe me, when you make a change - there is help out there (family, friends, social services, domestic violence numbers you can look up.)
And Elaine is so correct for saying - don't listen to sorries - it's a way to get you to stay.
Chin up friend!