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.
Among the most confirmed rights of the wife on her husband is to have sexual intercourse with her to the extent that he keeps her chaste and fulfills her right without him being harmed. This right is even greater than feeding her and the like. However, the scholars differed in opinion about the obligatory sexual intercourse with one’s wife; it was said once every four months, and it was also said according to her need and his ability. Shaykh Ibn Taymiyyah said: “This is the most correct opinion.” Hence, if the husband does not have sexual intercourse with the wife and she is harmed due to that, then it becomes permissible for her to ask for divorce. For more benefit on the situations when a wife is permitted to ask for divorce, please refer to Fatwa 84309.
However, if you are able to be patient with your husband and try to convince him about the matter of having sexual intercourse with you, or help him in finding a means of treatment if he has a disease, then this might be better because in general divorce has bad consequences on the children.
In many cases, the husband refrains from having sexual intercourse with his wife due to magic and the like. So, if you predominantly think that this is the case, then you may treat him with Ruqyah. For more benefit on Ruqyah, please refer to Fataawa 85500 and 88705.
Finally, it should be noted that a husband is not permitted to be absent from his wife more than six months without her permission as we clarified in Fatwa 85711. However, the wife should not ask for divorce just because of his absence but if she is harmed by this, then she is permitted to ask for divorce due to the harm.
Allaah Knows best.