I think you are much better off. Woman who cheats on her fiancée for 2 and a half years (she never had intentions to leave him. It doesn't take that long) has low moral standards. She clearly enjoyed your attention And sense of control over you. She'd cheat on you too. Abd nobody marries others because they have to. She doesn't have to marry him. She also didn't have to play games with you. Pretty much she isn't a good person. Heal, grieve and move on. Hugs