What is the ruling regarding expiation for this oath that my mother forced me to take by placing my hand on the Qur’an? And will Allah take revenge on me for invoking revenge upon myself if I returned, knowing that I have returned and my mother is the one who forced me to make that invocation?

The Prophet, peace and blessings be upon him, forbade supplicating against oneself, one's children, and one's wealth. The oath of one who is coerced is not binding, due to the hadith: "Lifted from my Ummah are mistakes, forgetfulness, and that which they are coerced into," and this is the view of the majority of scholars. Valid coercion is that which compels by threat. If there was no coercion, then the oath is binding and requires expiation. We hope that no punishment will befall you due to breaking the oath, despite the frequent supplication. One must be wary of disobeying one's mother, unless she commands an act of disobedience.