Drunk dad abusive towards mom, i don't know what to do.

My(23/f) father(55/m) goes out to drink with his friends in the afternoon at least 4-5 days a week, then sometimes he comes back drunk and starts abusing(not physical) my mom(57/f). He insults her and starts accusing her of all kinds of stupid things, then my mom, who goes to bed early as she is tired all day at work and comes back home to do even more chores, has to leave her bed and come sleep in my sister's room. He has been like that for years! No respect whatsoever, he has cheated on her, maybe still does, and he even gets angry at her cause he "believes she's turning us against him". We have grown up seeing him abusing my mother, i have seen him raise his hand on her. She doesn't even need to turn us against him, we have formed our own opinion. I don't know what to do, these situations really scare me and completely break my heart. I feel so so sad for my mother, nobody deserves a life like this. She has done everything for us, never thinking about herself. Whereas he spends his money on cigarettes, drinking and betting! He is my father and i can't not love him, but at the same time, i'll always feel an immense hatred for anyone who treats my mother like this! There are times when he is normal, when we are all like a normal family, i wish things could stay like that forever. My mom won't leave him. They have been married for more than 30 years now and she won't let go of her relationship, her children, her house, her whole life. We live in a rather narrow minded society where most elders don't see divorce as an option. I don't know what to do. We have talked to him many many times and he stops for a while but never for long. I'll be leaving the country soon to be with my husband and i'll never be at peace knowing what might be happening to my mom her. I know my siblings will be with her but most of the time they try not to interfere and i'm the one who sticks by her during those situations mainly because i'm the youngest one, since childhood i've been very close to her and i've always had it at the back of my mind that i have to protect her and be her 'shield' when my father attacks her. Sorry for having written such a long post. I'm not thinking straight right now, my heart is so heavy. I just wish i could give her my share of happiness and dissapear. I just want a normal family, a normal dad.

Edit: thank you all for your comments and encouragement ❤