Do you feel up to providing some more details? Posters who are knowledgeable in this area might be able to help depending on what happened.
I often see all the LTB and women's aide can help posts and I know the truth is that they can't always. Especially when it's emotional not physical, or physical but leaves no evidence, when it's he said she said in court.
Im not in the UK and the bar seems set even lower here. Mostly what my DH has done is emotional, he's made me feel worthless, he gaslites and twists things, he's scary when he's angry, he's made me and our eldest boys feel scared. But he's done absolutely nothing that would stop him getting 50/50 care, nothing that's provable and nothing bad enough. Where I am the only abuse that counts for custody is abuse against the child.
People can say all the he's abusive he won't get 50/50 platitudes they want, but the truth is that the bar is set far to low by courts and abusive men often end up with significant amounts of care. The best I can hope for is what a friend said, hopefully he won't be willing to go to court to get 50/50. And if he does get 50/50 hopefully he won't treat the kids the way he's treated me. But that's a lot of hopefully. I know I can't do this much longer.
The truth is sometimes you have no good choices left and all you can do when you can't take it anymore is take that leap and leave. You don't stop fighting, you keep supporting your kids every way you can, get them into counselling, give them a loving safe space and hope till they're old enough to be heard in court and they can say they don't want to see him anymore. I'm not scared for my kids physical safety and that must be so much worse. I'm scared that they will spend their time with him scared to anger him, walking on eggshells, feeling the constant churn of anxiety like I do now. That he will damage their minds, twists things and make them feel guilty. My two eldest boys have SEN and he isn't good at supporting them. DH won't even acknowledge what he's done so no chance of change. But no good options either. I can to some extent walk away, but he will always be my boys father. I feel the guilt of that. Sometimes all you can do is your best and hold on tight and hope.