What should I do, as my confidence in Allah's victory for me against the one who wronged me has been shaken, especially since the oppressor is my neighbor and my husband's brother, and despite the fact that I am wronged by everyone's testimony and possess good manners?

Do not grieve, for Allah is aware of His servants. The supplication of the oppressed is indeed answered, for the Prophet, peace and blessings be upon him, said: "Beware of the supplication of the oppressed, for there is no barrier between it and Allah." And Allah answers it whenever and however He wills. So, beware of despair and ill-thought of Allah. And you must examine yourselves and rectify your shortcomings.