What is the ruling on praying behind an Imam who verbally assaulted and publicly cursed me, and is it permissible for me to pray congregational prayers at home for this reason?

The Imam erred in reviling you, for reviling a Muslim is a transgression. However, one should not abandon congregational prayer in the mosque because of the Imam's action, for the Messenger of Allah (peace be upon him) said: "Whoever wishes to meet Allah tomorrow as a Muslim, let him observe these prayers whenever the call for them is made," and "Whoever goes to the mosque in the morning or in the evening, Allah prepares for him a hospitable abode in Paradise every time he goes in the morning or in the evening," and "Whoever purifies himself in his house then proceeds to one of the houses of Allah to fulfill an obligatory prayer from the obligations of Allah, one of his steps erases a sin and the other raises a degree."

Congregational prayer at home is sufficient, according to most of those who deem congregational prayer obligatory, if one finds someone to pray with in congregation, but one should be careful not to repeat this often.