sorry to hear it's happened for a third time. Thats sucks it really does.
This might sound bitchie since you've just got blackmailed but I mean it in the nicest way (I'm actually trying to help)
maybe it's time to change how you operate or how you find these people. Good people are out there.
Obviously what YOU are putting out there isn't working for YOU.
So what can YOU do to control it? Yep I said YOU because you are the one that needs too.
You've said blackmail but given little info. Blackmail is kink in Femdom are you alerting those into the kink? Or those whose intention is to scam and defraud? (report them wherever it happened. it's our job as kinksters to police our own. ok to late for you but someone else might be into same situation. If EVERYBODY policed our own. This would stop. If someone reported this "person" they would be around to scam you) Are you waving a preverbal flag to these people? It is way to easy for people to take advantage of male subs. You are on the bottom of the totem pole of kink and seem as an easy target. (a fact that lights a fire under me)
YOU have the power to control your situation. YOU are not powerless. Like Miki said don't put it out there if you don't want it coming back at you.
If humiliation is your kink, great work with it. Wear hood. Got body markings that are identifiable? tatts etc! Wear a zentai suit, cut out the parts you want exposed. Shoot images from the neck down. Use encryption or TOR if you have to. If your paying use pre paid. Do all the vetting you can. If you dont know what vetting is, learn. Find these people that are Domming you in the REAL community so you know there world too before you let them into yours. You can protect yourself and you can still get your rocks off! it's all in "now" you put it out there!
I have this annoying saying and I drive my subs nuts with "knowledge is a submissives shield" You have the power to stop it. Don't be victim. BLINDLY doing as told isn't submission..it is stupidity. Spend some time learning about what will keep you safe, in your situation.
Its not the kink world that is bad, its "some" people in it. Don't let "some" ruin it for you. Take back your power and give it to someone deserving not just someone willing to take it. That's not a Dom/me that's an opportunist!