What should I do about my adultery with my married cousin, who is on the verge of divorce, and what is my punishment?

Adultery is one of the most heinous sins and gravest major transgressions that Allah Almighty has forbidden, due to its evil path and its detrimental effects on the individual and society. Its punishment in this world is the execution of the prescribed penalty, disgrace, and scandal, and in the Hereafter, a painful torment. The abode of the souls of adulterers in the Barzakh (interim period between death and resurrection) will be in a furnace of fire. However, for one who repents with sincere repentance, Allah accepts his repentance and rejoices in it, transforming his evil deeds into good ones. The penitent is only required to repent and seek forgiveness. Repentance is achieved by abandoning the sin, regretting it, and resolving not to return to it, while concealing oneself and not openly declaring the sin, and striving in righteous deeds and expiating good actions.