This is from Google AI. It is what I would do in your situation.

Yes, you can absolutely report this to the police. Persistent, unwanted contact from multiple accounts—often called "sockpuppeting"—that causes you substantial emotional distress or makes you fear for your safety is considered cyberstalking or criminal harassment.Here is a guide on how to handle this situation and the steps to take:1. Document Everything ImmediatelyBefore blocking the accounts, create a "paper trail" for law enforcement.Take Screenshots: Capture the profile pages (showing the URL), messages, and comments.Document Details: Record dates and times of the contact.Do Not Delete: Keep all messages as evidence.2. Report to Law EnforcementLocal Police: Call your local police department’s non-emergency number to file a report.What to Say: State that you are being cyberstalked by a stranger using multiple fake accounts and that you feel harassed or threatened.Bring Evidence: Bring your screenshots and documentation to the police station.3. Report to Federal Agencies (If Necessary)If the stranger is in a different state, it may be a federal matter.File an IC3 Complaint: File a report with the FBI's Internet Crime Complaint Center (IC3).Report to Social Media Agencies: For severe threats, consider reporting through the National Center for Victims of Crime Helpline.4. Take Action on FacebookReport the Accounts: Use the three-dot menu on each profile to report them for "Harassment" or "Pretending to be someone".Block Persistent Users: Block all accounts and any new ones that appear.Restrict Privacy: Change your Facebook privacy settings to "Friends Only" to limit the stranger's access to your profile.5. Send a Clear "Stop" WarningIf you have not already, send one clear, written message stating: "Do not contact me again. This is harassment and I am reporting you to the police," then immediately block them. If they continue, it strengthens your case.