What is the punishment for an adulterer who intends to repent but is unable to do so, and what is the solution for such a case?

Adultery is one of the gravest major sins, and its punishment is severe in this world and the Hereafter. The most egregious type is adultery with a neighbor's wife. Nevertheless, Allah has opened the door of repentance for all sins, including adultery, on condition of abandoning the sin, regretting what has passed, and resolving not to return to it. The inquirer must not allow Satan to deceive him and push him into persisting in disobedience until death.