Mia feels irritated after meeting with Chandler again. Seeing his face again is aching her heart out and makes her head hotter that she didn't expect to think about revenge. No, she will never do that. She's not her mom. She's her. She won't let herself to be like her. She despised her to the core that she even hate her after knowing that she's her mom.
Her body feels heavy after thinking about those horrible things that just recently happened to her life. She doesn't want to suffer pain anymore. That's why she left. She left for the better and to give time and rebuild herself up. Chandler did break-up with her, not only her heart but also her entire world. That she needs to build a new one and start a new one.