What is the ruling on committing zina (unlawful sexual intercourse) when there are health and psychological problems and an inability to marry?

What you are doing is among the greatest major sins and destructive transgressions. Allah Almighty says: (And do not approach unlawful sexual intercourse. Indeed, it is ever an indecency and an evil way). And (And those who do not invoke with Allah another deity or kill the soul which Allah has forbidden [to be killed], except by right, and do not commit unlawful sexual intercourse. And whoever does that will meet the consequences. The punishment will be doubled for him on the Day of Resurrection, and he will abide therein humiliated). You must hasten to repent and increase good deeds, for the misfortune is greater than you can imagine. Repent to Allah and ask Him for help, sincerely strive to get married, fast frequently, engage in worship, and occupy yourself with what benefits you. Fear Allah Almighty as He should be feared, and make Him your refuge, for therein lies the solution to your problems and relief from your worries. Allah Almighty says: (And whoever fears Allah – He will make for him a way out And will provide for him from where he does not expect), and (Whoever does righteousness, whether male or female, while he is a believer – We will surely cause him to live a good life), and (But whoever turns away from My remembrance – indeed, he will have a restricted life). The Prophet, peace and blessings be upon him, said: "Whoever increases seeking forgiveness, Allah will make for him a way out of every worry, and from every hardship a relief, and will provide for him from where he does not expect."