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.
It is forbidden for your husband to contact this girl by phone or via the Internet, as this is a door to a great corruption. This matter is even forbidden if he had established with her an affectionate relationship; for more benefit, please refer to Fatwa 81356.
Therefore, we advise you to admonish him in a soft and gentle manner and clarify to him that what he is doing with this girl is forbidden. For more benefit on the prohibition of a Muslim man marrying a Hindu girl or establishing an affectionate relationship with her, please refer to Fatwa 87895.
Moreover, it is your right upon him that he should not be absent from you more than six months except with your permission. So, if he is not able to take you to reside with him, then you have the right to ask him to come back to you every six months. If he refuses and you are harmed by his absence, then you have the right to ask for divorce due to the harm.
However, we advise you to be patient with him as much as possible and you should continue advising him and not hastening to ask for divorce especially that you have mentioned that your family is in need of his help, hoping that Allaah will make a way out for you.
Finally, it should be noted that if you mean by your statement ‘I wrote about that girl on Facebook’ that you insulted her or defamed her, then you have committed something impermissible. The scholars stated that it is not permissible to insult a non-Muslim unless he/she is a belligerent, and that whoever insults him/her should be reprimanded by the Muslim ruler (or whoever acts on his behalf).
Allaah Knows best.