Init, you are one amazing person to survive all you have.
As for the 'low-life' in the story, he got 15 years raised to 20 yrs for using the ironing board. I don't know what happened to their child, but he never raised a hand to her. As in your case, she went back time and again for the DV to escalate, he hounded her at times to take him back. I think in the end she just gave up, people were telling her he'd never let her go.
DV is taken really seriously here in the UK, but it needs the victim to make statements and go to court, time and again they don't (I understand that, but it is very sad). My H is a police officer and they always make a DV call a priority, but the officers do find it frustrating going to the same properties and not being able to prosecute.
You're in a much better place now and stronger for it, such a shame it has to happen in the first place.