I just got aware of the fact that I am also responsible for all profiling and data-collection activities that Facebook does with my neat little Atomic Butcher: Homo Metabolicus page.
Unfortunately, as of now there is no way out but to disable the page entirely, to remain GDPR compliant. Sorry, if that means any inconvenience for you. You can always reach out via the means in the Contact section of this site (or on Steam).
Maybe Facebook provides a way in the future to allow small indies like myself to host pages there while remaining in line with GDPR; until then, no more Facebook.