Is it obligatory for the questioner to leave his job at the central bank immediately, or should he remain in it until another job becomes available, knowing that he holds a Pakistani passport and it is difficult for him to move to another job, but not impossible?

There is no harm in working at the Central Bank if the work is not connected to usury (riba) or direct assistance to it, such as issuing currency, holding the country's gold and foreign currency reserves, and controlling the money supply. It is forbidden to work in anything directly connected to usury, such as lending at interest to usurious banks, and determining interest rates for them.