TW: DV

my best friend of 10+ years got back with her abusive boyfriend, we're both 22 for context. they were together for a little over a year. she just broke up with him like two months ago and moved out of his house back in with her parents and i was so so proud of her, i know how hard it is. she told me after a month of being away from him that she hadn't felt that much like herself in a long time and i could see a change in her genuinely.

6 months ish ago she showed up to one of our hangouts with a black eye. she told me she got super drunk and fell down the stairs, i believed her because she drinks pretty heavily which is another issue in itself but in the back of my mind i had doubts she was telling me the truth. she had many many complaints about this man throughout the relationship to me like him not wanting to have sex with her, looking at other girls social medias, etc but never anything physical.

a couple months after that she broke down and told me everything. he gave her the black eye and they've gotten into many physical altercations, most of them being while they were both drunk. most recently after the breakup we sat in her car tg for hours and she showed me ring camera footage from their basement of a night they got into a huge fight, drunk again, because his ex girlfriend called him at 2am. i wanted to cry watching the video but i was more angry than anything. she was screaming at him to leave her alone and he kept pursuing her, saying that he wanted her to hit him. the camera cut at one point and in the next clip she was on the floor and she told me he pushed her down and she hit one of the weight bearing poles in the basement and had a huge bruise on her back. 

at one point she got up to go to her room in the house and he slapped her ass super hard. it was just disgusting. come to last week she texts me "i don't care what you have to say about this and we're not even gonna talk about it but i got back together with him." i held my tongue and just told her i knew she was going to because she had already told me they'd been talking and seeing each other again. 

sorry for the huge wall of text but i don't know what to do. do i just sit back and support her as best i can? she's not moving in with him again which is good. we both know she deserves better and she's such a strong and independent girl i don't understand why she would go back to someone who treats her like shit. i know thats much easier said than done, ik statistically it takes women 7 times to leave their abuser. how can i support her through this :(

my best friend got back with her ex bf