Ad nau·se·am

To a sickening or excessive degree; repeated so often it becomes tiresome, irritating, or unbearable.

He repeated his conspiracy theories ad nauseam, until even his most loyal followers rolled their eyes.

endlessly · obsessively · pathologically · ad infinitum · infinitely

From Latin ad (“to”) + nauseam (“nausea” or “sickness”) — literally, “to the point of nausea.”