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 ‘alayhi wa sallam, is His Slave and Messenger.
There is no doubt that the parents have a great status, especially the mother, as the Sharee’ah allocated for her three-quarters of the dutifulness to the parents. However, in what you mentioned, it seems that your mother has no sound reason for ordering you to take the initiative to divorce your husband, so you are not obliged to obey her, as obedience to parents is not absolute, rather it has limits which we have already clarified in Fatwa 131695.
Therefore, we advise you to be gentle and kind to your mother even if she mistreats you. You should try to convince her by seeking the help of some rational people and those who may influence her. But you should not forget about supplicating Allaah as there is much good in it. For more benefit on being kind and dutiful to the parents under all circumstances, please refer to Fataawa 87019 and 82254.
On the other hand, if a woman is married, then her husband has more right over her than her parents and obeying him comes in priority over obeying them. Also, the husband has the right that if he calls his wife to bed, she is obliged to obey him; if she refuses without a valid reason, then the threat mentioned in the following Hadeeth of the Prophet applies to her: ''If a husband calls his wife to bed (to have sexual intercourse with her) and she refuses, and he spends the night angry with her, the angels will curse her until she gets up in the morning." [Al-Bukhari and Muslim].
Also, the husband has the right upon his wife that she resides wherever he resides, so if your husband asks that you reside with him in Pakistan, you are obliged to obey him and it is not permissible for you to refuse (his request) or to obey your mother if she prevents you as long as you had not conditioned on him before the marriage contract to reside with your parents.
Finally, we advise you to be wise in solving the problems and to be keen on dealing with them in the way that causes the least damage possible.
We ask Allaah good for all.
Allaah Knows best.