Is it permissible for a husband to resort to masturbation when his wife abstains from his bed for long periods, for fear of falling into temptation, after many unsuccessful attempts to give it up?

Practicing masturbation is Islamically forbidden and an aggression against what Allah has made lawful. The questioner must convince his wife to obey him and warn her against non-compliance. If she refuses, he should marry another woman; otherwise, he must fast.