I will agree to follow Tommy on this one, but at least for your side of things have a conversation with her about your feelings and that you have noticed this, this, and this about y'alls relationship. There may be something going on with her that she may not feel comfortable or she may not think she is treating you any different. I know when i was sexually assaulted several months ago I treated my bf different and didnt realize it until he said something. I'm not saying she was but if you just abruptly end things you will always wonder why and having a serious conversation is extremely important for closure