I miss my best friend

My best friend recently stopped talking to me when I told her I didnt like her abusive bf.. they started dating 2 years ago when she was only 20 and him 35 with two kids from his ex... a couple of months into their relationship he started putting his hands on her and to make her forgive him he would take her on trips or buy her things.. Her mom passed away from cancer august of last year and she never found out about this man her daughter was dating. My best friend had no where to go so I offered her my house and she decided to go with her bf instead.. she started doing coke and other drugs with him to “help” her forget about what she’s going through. I’ve been knowing her since we were 8 and she’s a completely different person now.. before him she had three jobs, her own car, her own money and now she lost her car because of an accident HE got into and she works at a strip club and makes videos with her bf to get more cash... I don’t know what to do or say to her to help her anymore I feel like I’ve tried everything and when she would come to my house she said my place felt like a home and she didn’t feel like drinking or doing any type of drug to make her feel good and she always felt ashamed to tell me where she worked or what she would do to get money.. she even got stds and caught her man cheating multiple times and ended up getting beat for trying to confront him about it.. I haven’t talked to her in about 3 months (last time being when I went to see her and her man ended up grabbing my boob when she wasn’t around) I told him to tell her or I was and he did and as soon as I left her place I get a call from her and I hear them arguing and him hitting her while she’s begging him to stop.. I just saw on social media that she posted a selfie and has a popped vein in her eye and I KNOW it was because of him.. i hate that she’s going through this but she doesn’t wanna leave him... what can I do to help her???