Is it permissible to work as a manager of the computer department in an usurious bank in a country where no Islamic banks exist, knowing that the nature of the work is bad and causes depression, and that other job opportunities are unavailable?

It is not permissible to assist in consuming usury in any way, including working in usurious institutions, due to the Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." Consuming what is unlawful prevents the supplication from being answered and causes distress. Therefore, one must hasten to repent and abandon this work. Do not fear poverty, for that is from the whisperings of Satan, and Allah promises forgiveness and bounty. And whoever fears Allah - He will make for him a way out and provide for him from whence he does not expect. And "You will not abandon something for the sake of Allah, glorified and exalted is He, except that Allah will give you something better than it."