It doesn't matter if they know who you really are or not but it does matter if you either care if your content ends up on the internet or if they have the means to contact anyone in your circle that you wouldn't want to see whatever's being held over your head.
If you're worried about it in any capacity, I'd consider contacting authorities as it's illegal, at least where I live. If you are in the US, this page can give you some information on what can be done: https://www.fbi.gov/how-we-can-help-you/scams-and-safety/common-frauds-and-scams/sextortion
I will say this, sextortion has become the new "fake event" online that low hanging scammers are using to make fast cash. The harder working groups actually catfish people to get the the content then immediately use it to try to make some fast cash while the 0 effort crews just shoot a shitton of texts and emails out threatening to release something they don't even have.
If I shared content with anyone and they threatened to release it online, I wouldn't give two shits about it. There's enough NSFW content on the web where I could be confident that nobody would invest any more than a dismissive glance at my underwhelming physique and baby Napoleon.