All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.
Scholars have differed about the conditions which are stipulated by the wife in the marriage contract or before it but which are neither basic requirements of it nor contradictory to it. The majority of scholars held that these conditions are not binding, whereas the Hanbali scholars said that they are binding, and this is the preponderant opinion, in our view. For further information, see Fatwa 108196.
Therefore, your husband has to fulfill his promises and let you complete your studies and provide you with separate accommodation. Providing you with a separate accommodation is actually obligatory upon him even if this is not stipulated (before marriage), but stipulating it makes it even more confirmed.
As for your husband’s promise to take you abroad to live in that country and gain citizenship, then he is not obliged to fulfill the condition of gaining the citizenship if that country is a non-Muslim land. However, he has to fulfill his promise to take you there in case there is no Sharee’ah impediment, such as fearing being trialed in your religion or the like.
On the other hand, your husband has to repel the evil of his sister from you and he is not allowed to force you to stay with her in this case. If she lives with you in the same house and shares its facilities, like the kitchen, bathroom, passages and the like, you are not required to accept her living with you. Scholars have stated that the wife is not required to live with her in-laws. So, your husband is obliged to provide separate accommodation for you, and leaving the house in this case would not be not considered disobedience on your part. Moreover, you are not required to return to his house or live with him under such circumstances. For further information, see Fatwa 84608.
Nevertheless, our advice to you is that wise people intervene to reconcile between you. If reconciliation is achieved, it will be fine; otherwise, you are entitled to ask for divorce which might be the best option if there is no other way to repel the harm from you.
Allaah Knows best.