Bree3 - our family is blended too. No that's not right. We are a family in a blender and that is an entirely different thing. I really hate it when we seem to wear different colored jerseys clearly marked as opposing teams. There is a thing called Child Alienation Syndrome so you aren't crazy thinking that this stuff is something you're just making up or blowing up in your mind.
Your older children are paying a price too for your attachment to this man who is physically and mentally abusive. I know my kids have and while you can try to protect them from knowing the full extent of the abuse, they are living it too.
I for one am not putting up with it any longer. My kids come first. I may love him but I can live without him. My kids need me and don't deserve to live without me. Last night I took my kids to dinner at a nice restaurant to celebrate their first day back in school. It was so wonderful to hear about their day and listen to their enthusiasm. I gladly stayed present with them in those precious moments without worrying about what my AH was doing at home. It was blissful. I am planning to do more of that.
Listen to your heart. You do know everything that you need to know to sort this all out.