I am going to a sound a little judgemental but she sounds a bit sobby acting like shes your friend and then cancelling meetings. I think I would do my best to ignore her and act a bit positive and maybe try making friends with others it will lift your spirits and then you won't be worried about someone excluding you. To be honest facebook can be a downer sometimes when you see others hanging out and putting up pics and then your not there, it can make you compare your life to theres. So avoid comparing your life to others on facebook nothing is always what it seems or appears plus it is a bit unrealistic everyone has all there different paths and things to do. So many your pics are you on a yoga mat exercising energy and maybe your friends is partying with billy joel or something. It's how YOU feel about your life and situation that matters not weither someone else has a funnier life to you but underneath all those party selfies maybe alcoholism and depression you don't know. So don't compare yourself to others I know it can be hard especially now that technology can make you see what others are doing 24/7