How to respond to a blackmail or threat?

Save the messages.
Go to the police.

I read your 'About Me' and have an idea your culture and mine are different. So I can't know what other pressures hide behind this current blackmail threat.

But I do know this: Blackmailers and bullies travel in packs because the majority are terrified to do anything one on one. The worst way they can hurt you is for you to grant their power over you, to make you afraid and keep you afraid.

Don't hand them that power. If you haven't, starting now, keep screen shots of everything. Write down dates, times, screen names, websites, threats. If it's possible where you are, take the information to the police. If that's not possible, take it to others you trust, who have some sort of authority in your life - your family, a trusted teacher.

Your 'About Me' says you are a responsible kind person trying your best to get through life. Others will know that about you.

There are twisted people online and in real life who would simply get pleasure from watching you twisting on the hook. Others might carry through - it's hard to say. But the first thing you do (in any culture I understand) is don't suffer alone with this. Create your own pack. Fight the evil in them with the best weapon - the good in you.

They are trying to force you into fear and submission by threatening to reveal something. Reveal them instead.

Good luck, honey.

This type of crime has now elevated its profile with law. As stated keep note of everything state to the individual involved if they attempt to tarnish your character you will involve the police.

Screenshot the message. What's the threat?

police. There's pretty harsh penalties for social media blackmail in most countries now

Block them from your social media. Take a break and don’t acknowledge it. It’s childish.

Call the police. Do it. Chances are they will get those sick fucks, and they will have to pay for it.

I would say block them and report to facebook what they say they intend to do. But if you block them, you won't see if they do it or not. Sadly they can post on their own pages and you might not even know. If you know who it is warn Facebook.

But before all that. Save the messages you have and go to the police. Blackmail is a crime.

Don't respond to, get the police involved if you want but don't give them reason to think you care.

Wherever you live, call the police. In the US it's a crime.

I’d let them.

Get rid of Facebook.

What country do you live in?

Do you know who it is?

Dear me... I’m so sorry 😞

What is it they want to “shame” you over. ?

Report the user and block them. Can't think of much more you can do than that. Just be safe and be careful about what you let leak out there.

Facebook or social media are not the real world.
The internet is the world's bathroom wall, where cowards and fools post nasty gossip about others (they've never met) to make themselves feel superior.

If you delete all of the content from those accounts and close them, you take away any ammunition these putzes feel they may have on you. There is no law requiring you to have any of that garbage anyway.

Final note: Never put anything on the internet you wouldn't want your grandmother to see.

Ignore it. All they want is your attention and if they can't get it they won't have a reason to post it.

facebook is full of shit, and can be nasty

Tell them to fuck off.