Follow the exact same advice as people who are being blackmailed for money. This is called sextortion, threatening you to get more videos.
Online blackmail. Read this first. viewtopic.php?f=20&t=580Please read that entire topic. Here are the main points in it:
DO NOT PAY THEM! They will only be back for more money over and over until you stop.
^^ In place of this, do not say one more word to them. Block them everywhere. If you continue to talk they will continue the chase to get more of what they want.
Unfriend them then Block them in FB, change your FB username and picture. Increase your privacy settings in FB. Block them in Skype. Put Google Alerts on your name, and report any videos to the host of the website to close them. Do not answer any unknown emails, delete them without opening them, and do not accept any new friend on skype or FB.
Do not answer their calls and block the number if you can. If that does not block the SMS, then change your telephone number, Facebook will close accounts if he is impersonating you, or/and puts any of your details about you on an account that is not yours.
What is scammer's FB account profile link? Not just the Name you see on the account, as many people can share the same name, but the profile link in the address bar, the URL.
What is scammer's EXACT Skype Profile name and details there? (Right-click mouse on her name in Skype.)
Email address of the scammer? Or other chat profile name?