from your words, i found out your bf willing to get u back because u still love her, and not he love u, why the hell he still tell u that he still in love with that girl
my opinion, forget about it and start a new life, no point to get him back since his heart has no space on u

and sorry to hear that, hope u will get well soon, go travel or something might feel u good

let your bf fade away from your mind, don't remember him
i know the pain of breakup after a 4 years relationship, my friend suffered it before although i never had such experience
i believe your bf is attracted by the girl, his heart completely melt by the girl, he is still young and unmatured.
nevermind, u still young and got a bright future too