My " BEST FRIEND. " Ditched me, again for her boyfriend.?

The same thing happened to me! So i totally understand where you are coming from. Keep trying to tell her that. If the boyfriend is new she is obsessed right now and always wants to hang out with him. However give it a few weeks and she may lighten up. But talk to her and plan a day to hang out with her and let her know your her best friend who has always been there for her! :D