Reach out to your sister, if my sister was going through a bad time, I would find time for her. She would want to know I am sure.
I didn't tell people much before, just little bits and pieces. The reason I didnt is I didnt want people to think badly of him, like it reflected on me. This is a classic fear response to women who are being intimidated and controlled. But if a friend told me what you told me I wouldn't judge, but be there as support. A lot of the issues I had were passive aggressive and a lot of the time we actually got on and had a laugh. But it was cyclical, he was always a bit moody, but he has an inability to deal with stress and that gets pushed onto me.
You are fully capable of managing alone, just look at what you are doing now.
You are not a bad mother, infact you should be applauded for thinking you should leave, and trust me in the future your kids will thank you for it. Even though my kids heard a lot of him yelling at me and bad behaviour, they still want us to be together. I think most kids do at this age as its all they know. But essentially a happy and free mother who is not being intimidated is much better than one who is.
If your H says you are selfish, so fucking what. He is a selfish prick for exposing the woman he should cherish and his kids to throwing books at you and making you all cry. Its control. I bet he minimises everything too. i bet he tells you you are overreacting, I bet when you try to explain how you feel or any emotions he rams it back down your throat.
Hope you have a quiet weekend. In the final weeks I kept the peace as much as possible while I got myself sorted out. Good luck.