What is the ruling on a husband traveling for 11 months annually to seek a livelihood, and being compelled to practice masturbation weekly due to his distance from his wife?

Masturbation is forbidden, and it is not permissible to resort to it even once in a lifetime. One must repent from it immediately. Your distance from your family does not justify performing it; rather, the obligation is to seek lawful means to دفع الشهوة (satisfy one's urges), such as bringing your wife to you or fasting. It is not permissible to be away from one's wife for more than six months except with her permission.