Most women are walking around in the wrong size bras. Many don't wear bras out of choice. It doesnt mean anything. No one can draw conclusions fro that and say they should be ashamed, and nor should you be. He should be ashamed of himself.
Don't believe anything he has said about you. It is all lies. You are a great woman, a good mother, a strong and kind person. I am having to learn that the thoughts of being shit or stupid or rubbish or worthless come into my head, I have to capture them and say to myself they are lies and tell myself the opposite. You need to too. You are useful, look how you go to work, how you have asked for help here, and got away.
You are not a shit mum. Look how you have got them to a cm when you are at work, got them out and away feom that violent abuser, with documentas, clothes and toys.
You are not stupid. You have got away. Despite him brainwashing you into thinking he owns you and methodically undermining your self confidence, yiu have managed to take the essentials and get away from him to safwty. You really do not need him. Without him there is so much more real help available to you. You can live your life,free to choose your own friends, and meet who you want to, with your head held high.
Have you and the children eaten today? Try to eat something and aim to get a good nights sleep at the hotel or WA refuge.