Sorry to hear that.   The most important thing right now, is to stay calm.

Contact Law Enforcement

You should contact the authorities in your region.  Here are a few specific pages:

In the US:

https://www.fbi.gov/video-repository/newss-what-is-sextortion/view

In Australia

https://www.esafety.gov.au/image-based-abuse/action/remove-images-video/deal-with-sextortion

In the UK

http://www.nationalcrimeagency.gov.uk/crime-threats/kidnap-and-extortion/sextortion

Get Help to Minimize the Damage

There are firms who will help you such as Digital Forensics.  By utilizing such a firm you will minimize the risk of exposure of your personal information, pictures etc.

Don’t Pay Them

It might be tempting, but paying them is not assurance they will go away.  If they have electronic pictures of you, they will still have them, and can easily come back for more.  If you pay them once, no matter how small, they are likely to come back for more.

Act Quickly

You no doubt will have some embarrassment and shame to deal with.  What you did is not illegal.  Law enforcement and the firms that help you are professional.  There won’t be any judgement.