Concerning Unicorn Hunters, their behavior is gross. But, what if I (I’m currently single) want to be in a triad, maybe joining a couple, maybe finding two people who then get together. I have abandonment anxiety and am greyromantic asexual. I would want a closed polycule - be it triad, Vee, quad or whatever. Does that make me bad?
It is absolutely not bad to want a closed or polyfidelitous relationship. Wanting this is not bad; it’s how certain people go about seeking it that is bad. Just like wanting sex is morally fine, while sleazy pickup artist nonsense is not.
You’ll need to be clear and open about what you’re looking for and spend time in social and dating spheres where people are also looking for that. It may take some time to find, and you may encounter some obnoxious unicorn hunting couples, but literally no one has an easy time finding their ideal relationship!
I would caution you about one thing: you say that you have “abandonment anxiety.” That is not a relationship orientation, it’s a mental health problem, and it’s something worth working on rather than just indulging. Setting up your relationship terms out of fear, or because you think a specific type of relationship will keep you safe from painful feelings, is a recipe for disaster. It’s good to know your limits and boundaries, but it’s not good to just surrender to anxiety and let it define your relationships. Please talk to a therapist who specializes in abandonment and attachment and work on this issue - you may never be totally free of it, but it should not be a key determinant of your relationships.