All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
First of all, we recommend that you try to return to your husband and reunify the family if possible, even if it entails travelling to the country of your husband. This is the best option for both of you and for the children. The separation of parents has a bad impact on the children in general.
If it is not possible for you to return to him, and your husband will travel to his country, then children's custody is for the father. The majority of the jurists are of the view that if one of the parents moves to settle in another location [or country], then custody is for the father.
Ibn Taymiyyah said: “... If the father is residing in a country other than that of the mother's, then the custody of the children is for him and not to the mother, even though the mother has the right to the children's custody if the father and the mother are living in the same country. This is also the view chosen by the Imams of the Four Schools of jurisprudence.” [End of quote]
It should be noted that it is not difficult for the children to learn the language of the country where they will live with their father, especially that they are still young.
Finally, our advice to you as a righteous couple –and we think that both of you are upon much goodness –is to take into account the interest of the children and endeavor not to make them victims of any dispute between both of you. Reconciliation is better.
For more benefit, please refer to Fataawa 258490, 263320, and 213352.
Allah knows best.