What is the ruling on a person invoking a curse upon himself, wishing to be deprived of his mother if he were to see a certain individual, and then regretting that invocation after a period of time? Will this invocation be answered? And what is the way out of this predicament?

There is no doubt that what you supplicated with was a mistake, for the Prophet, peace and blessings be upon him, forbade supplicating against oneself, one's family, and one's wealth. What is incumbent upon you is to repent to Allah for this act, and we hope that it will not harm you. You must strive to supplicate for yourself and your mother with good.