Not sure what to do right now, long post, but help is greatly appreciated

I met this girl in 7th grade, and now its freshman year in high school. We have been through a lot together, we dated a few times, we were each others first kiss, and we are still friends (at least I think so). So earlier in the week, she cut her wrists pretty badly, and her mom found out. Don't go assuming she's emo or anything like that, she has it rough. Her parents got a divorce earlier in her life, the boy she likes doesn't like her back, and others I wont get into. She likes a boy named Max, and they dated late 7th Grade into 8th Grade for about 5 months. She doesn't just like him, she's basically in love with him. Thats not what I need help with. So back to the cuts on her wrist, she cut herself because Max and another girl, Claudia. They aren't dating, and he doesn't like her. But she sees them talking day and night, and that hurts her. He texted her about midweek, and their discussion got to their relationship. He said he was offended people thought Claudia and him were dating, as many people had asked. He said that he had learned from his mistakes, and he wouldn't make them again. I do not know what he was talking about, but she seemed to know. Already, we used to Facetime every night for about 3 hours, and we would text the rest of the time we weren't at school (mention I have nearly every class with her, and we walk in the hallways together). He knew about our Facetimes, but thats not what bothered her. Back to the story, she Facetimed me that night, and was crying. She had about 12 cuts give or take on each wrist. She told me what had happened, and we talked for a while before her mom walked in. She wanted to know what was going on, and my friend successfully got her out of her room before she saw the bloody knife and gauze. I was left on Facetime for about 30 minutes, and when she came back, she told me she told her mom everything, about the cuts, and what max had said. We said goodnight about an hour after, and at 1 AM her mom walked into her room, saw the knife, gauze, and freaked. She bandaged her daughter, and woke her up to talk. Her mom wanted to send her to a mental clinic, and she texted me at ~1:30. I was sleeping, and the next day while we were at school, her mom calls my mom and they talk for a while. When I got home, my mom sat me down to talk. She said that both her and my friends mom had talked, and agreed that our relationship was not the most beneficial for either of us. A lot more was said, but thats not important. Her mom told her that she wasn't allowed to text me, Facetime me, hang out with me, and to minimize talking at school. Well we still talk at school, and both of us both agree that it wasn't fair in the least bit to do that. I understand and respect that her mom is trying to protect her daughter, but I feel that It was extremely unfair to tell me that we couldn't be friend anymore, but not Max, or anyone else. I absolutely hate her mom right now for taking my best friend away from me, and I have no clue what to do. I emailed her mom a few time, and only got one shot back, so I am in good terms with her mom respectively, but I want to convince her that Its not me, and that her daughters and my friendship is beneficial, as I have helped her through hundreds of problems, and we are basically siblings. I know pretty much everything about her, and she knows me even better. I know this is a long post, and I hope those of you who had the patients to read through this can help me, as I really need it right now.