I understand you feeling hurt by your girlfriends actions. I think your gf's explanation woud hurt me even more...had she said "it did not mean anything" I would have explained to her that is exactly why it hurts. Sounds like she is not even taking your consideration anymore...what changed. Also when people still fight and then make up but still fight, there is usually an unresolved issue. It does not seem that she is taking this relationship seriously. Perhaps some counseling would help. I hope she did not treat you this way when you were still just best friends.