Stalker in another country found out my full name.

Last month I was messing around on Bumble and ended up paying for premium and putting my location abroad. I started chatting to someone and we moved to whatsapp. The conversation got a bit dirty, naughty pictures were exchanged etc. (All consensual). Eventually we stopped talking... or rather I guess you could say I ghosted the person.

Since then, they've messaged me a few times over the last 2 weeks, to which I didn't respond. Then suddenly yesterday they hit me up with my real name. I got creeped out and blocked the contact but this morning had second thoughts, decided to unblock and explain I'm sorry for ghosting, not interested anymore etc. I asked how they got my name and they responded saying they found my phone number on PayPal, with a screenshot of it.

I said let's stop talking, they called me an ahole and I blocked the number. An hour later a new message popped up on WhatsApp from a different number saying "ahole" and that number has since messaged me a few times with similar content. I'm a little worried about this. If they know my name they can find stuff about me online. Not so much social media and friends but more professional stuff like my work webpage and email, and linkedin, as well as various publications (I'm a researcher). My mum has made a few posts with my name in them on linkedin so if they tried really hard they could find her. Needless to say all my privacy settings are on maximum, but the stuff with my mum's posts can be found even with the privacy settings up.

What could happen from this? And what steps can I take? I'm not sure if they're planning to blackmail me somehow or they want to embarass me publicly... really not sure and I don't want to interact with them anymore so that I would find out. I'm quite scared...