I live in the EU and Facebook has blocked access to my account unless I accept their privacy rules, which means giving up GDPR protections.
Facebook operates in the EU and has EU data subjects, therefore Facebook is subject to GDPR.
You should be able to withdraw your consent. Article 7(3) says:
The data subject shall have the right to withdraw his or her consent at any time. The withdrawal of consent shall not affect the lawfulness of processing based on consent before its withdrawal. Prior to giving consent, the data subject shall be informed thereof. It shall be as easy to withdraw as to give consent.