Friend problems.

It all started when we first met. She wan't really like me. She was kinda "preppy" in a sense. But as we hung out more she started to adapt my style. Well when you stand out like I do, you get bullied. I have always dealt with it. I never let it bother me but she couldn't really handle it.. It started to break her down.. She seemed fine but I could tell something was up I didn’t know what it was. I thought she was okay for a while and she just continued to get worse and worse and I didn't know what to do.... I noticed that she cut herself... I didn't know what to do.. I didn't know whether or not I should tell I was so confused I didn't know what to do. I tried to talk to her because we were closer than most friends. We were really really close. Not dating but sometimes it seems that way. SHe wouldn't budge.. and I knew something was really wrong if she wouldn't tell me. I still didn't know what to do so I tried to help her through it but I couldn't.
Then I noticed that she wasn't eating. I would ask her why and always she told me she wasn't hungry. I knew she was lying.. but again I had no idea what to do.. Well it went on for a while and then she started to eat and I didn't notice anymore cuts. I thought she was making progress so I didn't say anything to anyone. Well it definitely didn't get better. She started to visit the guidance counselor quite often and I thought it was good. And it was. But I was standing in line at a concert. (Asking Alexandria if you were wondering xP) and I got a text. It said "They are sending me away" I was confused(Yah, I get confused alot) and so she ended up telling me that they were sending her to a mental institute. We were cut off for almost 2 months.
My lifeline, my best friend, my everything was gone. I was slowly losing interest in everything. I was just kinda sad all the time.. not really depressed but I just got sad a lot and I didn't know why. And eventually she came back. She was released and so she came back to school. She wasn't there all day she would just be there for a few periods. I thought she was doing good. Long story short haha I am really dragging this out >.> she was back for a while and I still wasn't doing good since she was gone. even when she was back I wasn't doing good. I didn't know what was wrong with me but I didn't want her to worry about me so I tried to hide it but I didn't do that very well. And we started to grow apart a little and she kinda started to seem sad again. Not like she was but she kinda seemed off and distant alot. When she saw me she would light up but when I wasn't around she wasn't bright and shiny like normal. and today yet again I got a text and they are sending her back. I am really upset... I don't really know what to feel. I don't want her to leave but I want her to get better. She said that she will be gone for an even longer period of time.. I want her to get better so so bad. I feel so so terrible for her... I know she is in pain and it seems like I can never fix it.

Just looking for some opinions... help... anything.