When should I call it quits?

My husband and I have been together for 7 years. He has always had an anger management problem, which he swore to correct before our children started to behave like him. Now my son who is almost 6, acts just like his Dad. Not to mention that their Dad finds it okay to yell at me in front of the kids and my friends. When the kids see him disrespect me, they give me the same treatment. My trouble with the entire thing is the fact that I am only 28, and I have already been married and divorced once, and I swore to never do it again. Yet it seems that things are steadily getting worse between him and I. I even suggested having an open marriage, hoping that if he were to spend some time with other women, maybe he would be in a better mood. His self esteem is bad, he won't even try to act upon my suggestion. I hate feeling trapped, and I don't want to take the kids from him, but I feel like it is to the point that they would have a better outlook on life if they were to get out now.