Is masturbation permissible when there is fear of psychological and social harm, especially if the person is unable to marry and suffers from health conditions that have led to their repeated rejection for marriage proposals?

Testicular atrophy is not a defect that necessitates disclosure if it does not affect intercourse or enjoyment. Masturbation is forbidden, unless there is a strong presumption of falling into fornication, in which case it becomes a matter of committing the lesser of two harms. There is no justification for masturbation in your case, and adherence to Islamic injunctions such as lowering the gaze and fasting obviates it. The statement that masturbation removes anxiety is incorrect, as it causes worry and health and psychological harms; and patience with the effect of desire in obedience to Allah is better than masturbation in disobedience to Allah.