I cannot understand why he doesn't miss not seeing me or want to see me more and make the effort to do so.
I don't particularly think neither his behaviour nor yours is mysterious.
Sex can be so addictive when you are much younger.
I have gone past that stage ages ago.
Do I miss it? Hard to say. . . .
You are once-a month "fuckbuddy" where sex is the main and he likes it that way.
You love it as well.
He does not want it all the time, understandably.
Maybe, he likes to do "relationship" stuff with someone else, who's more relationship-orientated lady, cooking, going away together etc?
Could he be a little older?
He sounds like he has lower sex drive than you.
Or, he might be open to seeing other women if you don't live together.
Or already in a relationship with someone else i.e. wife that he would not want to discuss that she even "exists". Do you know his status? Single, married etc? Do you spend time in "his" place?
He plays a role that he cares about you and he might/does in his own ways.
He enjoys playing with your emotions (about whoring) which might be part of this d/s dynamics.
You might find it exasperating but spend hours chatting on the phone (that won't help the matter in a real sense but maybe sexually, it does).
Strong emotions can make sex even better.
It's how it "feels" like that drives you at it.
It's almost like a drug/roller coaster ride.
If your priority is hot sex, fuckbuddies are not so bad.
You can stay on that exciting ride for a little longer,
sometimes, it's too good to get off.
I'm sure you have a special bond.
You could enjoy the ride for now until "enough is enough" hits you.
If once-a-month action / "arrangement"
is not enough, then you need two more men to keep you busy.
Maybe, escorting makes it up (?)
This stage usually passes after a certain age group.
I often think it's hormones.
Nature telling you to have sex.