Help with cat and boyfriend issues?

I moved in with my boyfriend and its really opened my eyes about how much I do not love him and I really want to break up with him. Long story short: he's emotionally abusive. Problem is, we both have a kitten named Dahlia and he pays for her vet bills. I want to keep her so badly, as I am so attached to her. I'm afraid if I leave to go back home he'll keep her. She doesn't even like him she runs from him and hides under the bed when I'm gone. I'm the one who takes care of her. I feed her, bathe her, clean her litter box, etc. I'm afraid if I just leave with her he'd call the police and have her taken from me. Plus we have 4 other cats at my house and I know he'd play the card that we have too many cats. We are sure to always provide them with food and love. We make sure they never go hungry. I know most people say "its just a cat" but she is my baby. I woke up with her when she was a kitten and would feed her her formula (she was too young to be taken from her mom, but the girl who had her couldn't take care of her). He's also hurt another cat that we had (she's currently living very comfortably with my family), she "pissed him off" so he grabbed her head and squeezed it (not hard but still it pissed me off). I told him that if he ever hurt another cat like that again I'd leave with the cats and call the aspca on him, he hasn't hurt another one since. My question is, is there any way that I can keep her in case he does want to press charges or something against me? Please help, and please only mature and helpful answers only.