What is the ruling on a husband abandoning his wife and preferring masturbation and conversations with women over marital relations with her, and is the wife or the husband at fault? And what is the solution?

Masturbation is forbidden, and its occurrence from a married person is even more reprehensible; for it involves ingratitude for the blessing of a wife, and indicates a sick heart. One who is like that is not unlikely to commit masturbation or something more heinous. If he is negligent in fulfilling Allah’s rights, then how can he not be negligent in fulfilling your rights and wronging you? Abandoning a wife is not permissible except with a legitimate شرعي justification.

You did well in advising him, and the fault is on his part. Therefore, be patient with him and continue advising him gently and kindly, and pray to Allah to rectify him. Your adornment for him and your good marital conduct might divert him from thinking about others.