What is the way to lower the gaze and control excessive sexual desire, especially after intercourse and during the wife's menstrual period?

We advise the questioner to fear Allah and to stay away from anything that arouses desire, especially following up a glance with another, as Allah Almighty says: ﴿Tell the believing men to reduce [some] of their vision and guard their private parts.﴾ [An-Nur: 30], and as the Prophet ﷺ said: "Do not follow up a glance with another."

If you are able to marry a second wife and you believe that this will subdue your desire, then you should do so, while adhering to justice. For whoever fears falling into a forbidden act if they abandon marriage, then marriage becomes obligatory upon them. If you are not able to marry a second wife, then you must fast, for the Prophet ﷺ described it as a "Wija’" (a means of castration/curbing desire), because it cuts off desire and weakens it. In the Hadith: "O young people, whoever among you can afford to marry, let him do so, for it is more lowering of the gaze and more protecting of the private parts. And whoever cannot afford it, let him fast, for it will be a Wija’ for him."

If your desire does not subside, there is no harm in presenting the matter to a doctor and taking what calms it, while being cautious not to take anything that completely eradicates desire; for that is forbidden and impermissible.