Did a supernova in the Sirius star system propel the Anunnaki planet, Nibiru, into deep space, resulting in its coming into our solar system every 3600 years?

This indeed is the case, that is their true origin, and what set things in motion to create their great difficulty at present. It is part of the legacy of karma they have brought down on themselves. The unfortunate thing for humanity is they are present for the end stage of the downfall of Anunnaki and are in a poor position to stand up to them and their superior capabilities. Still, this is the task at hand, as you know, to stand strong and enlist divine help to re-balance things in favor of humanity and find a solution that will be nonviolent but will free humanity once and for all from their grip.