Most Helpful Guy
Sadly there is nothing you can do. She apparently has some severe obsessive / depression disorder and needs professional help. Sadly you're hitting that age where you're going to see people you thought you knew so well change, sometimes for better, sometimes for worse. The only thing you can do is be there for her if and when she decides to come out of her hole.
Most Helpful Girl
OMG... what a jerk he is? does her family know the reason she acts like this? if not you should talk to them and help her because she really needs you right now! try get closer to her again and explain why you stop hanging out with her.. i also think that you need to have a talk with that "boy" and inform him what he caused.. i am really sorry for your friend and i hope she gets over it... good luck and keep us updated:)