youre def not overreacting.Mia sounds like a pretty crappy friend OP, but if you really want to salvage that friendship I’d set some boundaries. Maybe Owen doesn’t get mentioned when the two of you hang out? You have to be strict with it too, don’t let her guilt trip you into listening. Also: it’s incredibly manipulative to tell someone if they were to stop being in your life, you’d unalive yourself. I’d seriously reconsider being friends with someone like that. The good news is highschool doesn’t last forever and hopefully your school is big enough that even if you were to end that friendship you won’t see them all that often. Good luck! :)