Cutting is Not the Cure for a Broken Heart, Ice cream and cookies are! [Mappie needs advice]

So my best friend has some drama to deal with. Our best guy friend likes to talk to us about his girl problems. Up until recently, he's been telling me about how he likes my friend. She kinda knew this because I told her (before you throw tomatoes at me, let me explain). He told me I could tell her, but he said he probably wasn't going to pursue it until he felt the time was right. So I told her, and she was giddy, to say the least. She didn't really like him at the time, she just has really really big self esteem issues and she only feels like she worth something when guys compliment her. But anyways, a couple of days later he asked her to a football game (well he invited us both, but I hate football, so I didn't go), which they went to and yada yada. She had fun, he had fun, and so for a while they did stuff like that. They held hands, never kissed, but in her mind, they were kind of a couple, even though they didn't make it official, but there were tons of rumors flying around school that they were.

About a week after the dating epidemic, where they were going out on dates like every two days, he walks up and tells me that he really likes this other girl at school. So obviously I was like, "What?!" because he had probably gone out on like five dates with my friend. I knew my friend would be crushed, but I didn't have the heart to tell her, unfortunately, she found out because of another rumor.

So later she asked him about it, and he told her how he really like this other girl. He was telling her thinking that she only thought of them as friends, and that he never really intended on the football games being dates. So she acted totally cool with for a really long time, giving him advice about her, and how to make her like him, but on the inside it was really hurting her how fast he had gotten over her. Apparently, she has been cutting. When I saw her scars, I got really really worried, and she told me about how much it hurt her to see him move on. Now she thinks she really ugly and disgusting, even more than she thought so before! I keep telling her that she can't let him influence her mood like that, but she says she can't help it. She's becoming obsessed with him. Whenever she talks to him she's always so happy, but when he doesn't talk to her, or he talks to the other girl, she gets really depressed and gets down on herself.

I tell her she beautiful and slim and pretty all the time, but it doesn't mean anything coming from me. I tell her that she can't rely on guys because they won't always be there for her, but she just can't wrap her mind around that. Of course her mother isn't helping much either by telling her, and I quote: "When you get rid of your acne, hairy arms, and braces you'll be drop dead gorgeous!" I just can't believe she said that to her! Her own mother telling her about how she needs to change before she can be beautiful. She already is beautiful, but she just can't see it, and because she thinks she's ugly she's causing herself physical pain and I'm worried she'll do something she'll regret. Help me please?