You may feel like you want to punch yourself but from the outside looking in I want to congratulate you because you are being very courageous.
It is incredibly difficult to report someone you love to police, much harder than reporting a stranger or someone who has been consistently abusive. So well done.
Try to be patient with yourself, you have - and are still going through a traumatic ordeal and you need time to process what is happening. You also need support - from professionals and trusted friends/family if all possible.
Family harm is complex. Most women (and I say women because in the main it is women who are beaten by men) try to leave 20x before they manage to end the relationship. That in itself is an indicator of how challenging it is to stand up to an abusive partner.
Staying away can feel lonely and also scary with conflicted feelings around guilt, loss and relief.
Try if you can to focus on your own needs rather than his or his children's. Firstly because you need to heal and secondly because the best thing you can do for him is to give evidence against him so that he has to confront his demons. It's also the best thing for his children. But mostly it's best for you, you need time and support to accept how you ended up in this situation and to learn to care better for yourself.
You deserve better and once you heal, you will naturally care better for yourself and keep your distance from abusive people.
Don't give in to the negative messages in your head, that's your self loathing trying to get through. You can do this x