Have you ever lost one of your bestfriends?

Okay, so I've been like bestfriends with this one girl for the past year. I'm talking inseparable and not able to go a day without talking. She's two years older than me (grade wise) but shes almost 3 yrs older than me (age wise). We started growing apart and not talking that much after Christmas and the only reason why she would even call me after Christmas break was to ask about something about her new itouch because I have one. Then in january she got a boyfriend and started hanging out with other people which I was totally fine with but it was just the fact that she would start to ignore me in school and it was hurting me because she was supposed to be one of my best friends. I started argueing with her about all of this and I ended up talking to her about it during lunch at school one day and I just broke down (not just because of the whole situation, but because I had so much other stuff going on with the new semester starting and another situation thats even more complicated). I talked to her that night on the phone and she said she felt bad because I was really upset about it while she didn't show any emotion towards the situation. I told her that I just don't like losing people in my life and I felt like I was losing her as a friend and I know that she knows what it's like to lose people so shes used to it. So, one day she just randomly texted me and asked if we weren't friends anymore and long story short, she just ended our friendship right there. This happened about a month ago. Later, she told me to stop talking to her and she would stop talking to me and she just didn't want me in her life anymore. I was pretty much devastated because here I was, under the impression that I was pretty much like a younger sister to her, and she just says that to me. She says I was jealous of all the things happening in her life which I don't now where she got that from but whatever. And the thing that really makes me upset is the fact that she really doesn't care that we're not friends anymore but I do. Im really upset about it still. This'll sound pathetic, but I've cried over it numerous amounts of times because it makes me sad. I don't really know what Im trying to ask, but I guess I just needed to rant to someone. Has anyone else lost someone like this?