I read it and screamed in my mind "That's me!", but I don't relate to the rest of the post. This thread is so good and made me think about my sexlife in ways I didnt before.
In general I'm a person with high libido who loves sex and often can't seem to focus on anything else, but then when I have a long break, like a month, it just turns off? Also when I crave sex I want sex, no masturbation fixes it, I just need the interaction with another human.
So when it happens and I don't have a current fwb I'll look for dates on apps, I look for people who tick all of my boxes, or rather who aren't repulsing to me. And these things are mostly not body related. And then when I meet them I don't fantasize about fucking them as people, but about the act of having sex itself. I will talk with them, get to know their kinks and I get turned on by the idea of having sex with a person with those kinks, but don't connect it with whoever sits in front of me. I know it all seems dehumanizing, but I don't feel that way in the moment, I also get off on caring for the other person's needs in bed. With knowing that person and meeting them a few times they somehow merge into a real human when I add the platonic attraction and so fwb forms for me. When I fantasize about sexual things I use a gender neutral, faceless idea of a person in them or my current sexual partner's body in it (might be connected to me not being able to form an image of someone's face in my brain)
I also get turned on when I see someone's body, but I will just think about certain body part, it's never the genital area though.
And, to make things complicated, I seem to almost never be attracted to people I started with as platonic friends, but I can turn fwb into platonic friendship and back.