It can be very hard to prove you have been dating a evil and crule person...
These type of relationships take time to heal or you have to say: it is time to move on... Unhealthy relationships can be a danger to you or the children, be it if you are a man or a women.
If a partner has drug issues then maybe they are not well to take care of your wellbeing as much as them.
If a partner likes to use the fist on you or children then maybe the situation is not healthy.
A partner may need to seek recovery healing methods, as much as you seek your own healing help also.
It does not make you a bad person asking or seeking help, the main issue is something is not working right. So a change is going to have to happen.
But also remember some situations are very cruel and evil, and some People can be very cruel in a evil way, but you don't have to play a part in being this way also.
To get away from cruel and evil situations you might have up and go or send the other packing, but watch out for danger or your own personal safety also.( I wish you good luck to exit and recover. )