Good for you!
I read every word. I, too, was abused. Physically and emotionally. A year ago, I finally cut my abusive mother out of my life, and it was the best thing I've ever done.
I know that it doesn't feel like it right now, but in the not-too-distant future, you will look back and feel relieved, and empowered. You did the right thing for yourself and for your children. Seeing them is a privilege and a blessing, not a right or a duty.
One thing that strikes me, is that you may be feeling guilty right now. I'm not sure if any of things apply to you but they may be a start to help you on the road to healing:
Boundaries; When to say YES, When to say NO
Codependency No More
Only you know the severity of what you experienced, but this may be something to check out - it's a resource center and support group for those that have an individual with borderline personality disorder in their life (it's rarely ever diagnosed, so don't think it doesn't apply just because he doesn't have a diagnosis) or individuals that display similar traits. - http://www.bpdfamily.com/