Someone PLEASE help me understand my ex-girlfriend? :/?

Well, you kinda answered your own question. She sounds f****** mental dude. From the sounds of youself, you come across nice and well educated. There are plenty of girls out there that would be much nicer than her. Ignore the attention seeking ***** and let her ruin her own life. You need to move onto bigger and better things like you said. Think of it logically, not with emotions. They might delude you. She sounds like a bad influence so just leave her.