i'm stuck, and i dont know what to do.

i have(or had, im not sure) a friend who became my best friend last year, but nowadays all they know is being rude to me. sometimes we fight, and other times we don't. i have problems with attachment, so.. i easily developed feelings for them. which has probably been draining me because recently they started dating someone else, and now im supposed to pretend i dont care just to keep them as a friend. or, that is what should happen, but they are really narcissistic and dont really care about me. we're about to cut ties soon.. ut seems, but i still have feelings for them, but they dont like me and i seriously dont know what to do. maybe venting publicly isnt a very good idea, but i have no one else to turn to. im really stuck.