Sounds horrific Algarvetammy
Addiction creates a vacuum if chaos , anyone in proximity gets sucked into it. I feel so much for you and especially your dad, no one should be treated like this by their own children ????
I’m struggling to walk away from my husband even though I know I have to to survive now , so I can’t say oh just walk away from your brother and friend as if it’s easy. But it would be for the best. No contact at all is what’s needed, so they can no longer manipulate or harm you or your dad.
As for Your friend, she is big enough to work things out for herself, she’ll have to ..you warned her , and she’s chose her side… Due to her very close contact with your brother I think you need to cut all contact with her too, she’s your brother’s pawn, he will continue to abuse your family through her.
My heart goes out to you , such a sad sad situation