Hi Anne, hope you're feeling better today.
I don't think you're weak. I think you're scared. Scared of your husband, scared for your children, scared about being seen and accused of overreacting. To you at the moment the idea of contacting any kind of authority seems a step too far and I think you're worried both that they will dismiss you (they won't) or that others will believe you're being dramatic (especially as we all know, including you, that your husband will use this against you). Some people may think you have overreacted- who cares? You know what you saw.
It must be difficult when you're so involved in huge situation and have so much history with your husband, so let me ask a question-- if you had seen exactly the same situation occur but it was a stranger in the street doing that to his children would you stand by and watch? Or would you call the police?
I do understand that you didn't just watch him do this, you did try and step in, but unfortunately by choosing to stay with him you may as we'll be standing by and letting this happen. Realistically, looking at the situation and your husbands complete lack of guilt and remorse (and the added extra of him blaming and controlling you) I think it's fairly safe to say it's not a case of if he becomes violent again, it's a case of when. So, essentially, you're just waiting until he lashes out, hits and becomes violent to your children again. Would you leave your children in the care of a stranger (babysitter, childminder, teacher etc etc etc) that not only had a history of violence, but a history of violence against your children? No, you wouldn't. So why him? Just because he fathered them?
And if your response to that is "well after yesterday I'll never leave them alone with them" then what is the point in staying with him? This is a man you cannot trust to be alone with your children, what hope do you ever have of making it work and being a family unit? Realistically, I'm afraid the answer is none. I think deep down you know this, but you're scared. You might be able to paint a picture of how wonderful things could be if everything were normal and it could magically sort itself, but the reality of the situation is very different.
My advice? Even if you think contacting police and SS is a step too far, you really should not be with this man. At all. Just bear in mind that if you divorce without informing the authorities of what he's done he may want joint custody and access rights, and then you won't have the ability to be there standing in between him and your children. Perhaps a first step could be you telling someone else you know- a friend, your mum? Because I bet you've kept this to yourself.
Take care Anne, I really hope that you realise you have no reason to be scared and do the right thing 