1) Khushi leaves or is thrown out by Raizada. Akash treats khushi as a little sister. Khushi return because of her dad maybe. It is revealed to the family that Payal had called Khushi multiple names and accused her of seducing Arnav and Shyam despite the fact she knew about the engagement. Khushi reveals that Payal actually wanted to marry Arnav. Khushi is staying in a hotel and Arnav comes. They end up sleeping together. Khushi next day calls in one night stand. Later Arnab finds out Khushi is having health issues and only way to resolve it is by Khushi staying in India and dealing with issues. Payal comes to meet Khushi and accuse her again which causes Khushi to have another attack but thankfully Arnav comes in time and save her.
2) I don't remember much but no support Khushi when she tries to reveal Shyam truth other than Akash, NK and maybe Payal and her dad. Khushi leaves with her dad. After his death the truth is revealed. But Khushi refuses to forgive. She is living in an appartment with NK help and trying to become independent.