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 is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First, we ask Allaah to reward you for your zeal about your religion and being keen on raising your children according to Islaamic morals and standards. Normally it should be your husband who should have this feeling as he is the person in charge of the house and he is responsible in front of Allaah. If your husband is as you have stated, then he is wrong in two regards:
Firstly, he did not fulfill the condition he agreed to fulfill. So it is an obligation on him to honor this condition, as the Prophet said: "The most conditions that are worthy of being fulfilled are those with which you made the private parts of your wives lawful (i.e. marriage contract condition)." [Al-Bukhari and Muslim] Moreover, this condition is more confirmed as it is in accordance with the principle that it is not permissible to reside in a non-Muslim country without a necessity.
Secondly, he is helping in consuming usury and interest by dealing with banks that deal with usury and interest. Allaah says (interpretation of meaning): {Help you one another in virtue and righteousness. But do not help one another in sin and transgression. And fear Allah. Verily Allaah is severe in punishment.}[5: 2]. So advise him and remind him of Allaah, and that his act leads to a bad end, especially by exposing his children to the danger of residing in that country. He could face the punishment in this life before the Hereafter. It might be that they would be brought up according to the traditions and customs of that country. So they could adopt bad morals and cut relations with kin, so he would be the loser, and they would lose their worldly life and the Hereafter. Therefore, first seek the help of Allaah then the help of whoever you think can influence him, especially scholars and righteous people. It might be that he will take heed and become righteous; if so, all perfect praise be to Allaah, otherwise we advise you to be patient and continue to advise him and not become complacent. You should nurture your children according to Islaamic principles and good moral standards, and try to link them to some good television stations and some good internet websites. As regards your dwelling in a house which was bought on interest loans, then there is no harm on you, Insha Allaah.
Allaah knows best.