Huh. I wouldn't have realized it was a Myers–Briggs Type Indicator test if they didn't have the images alt labeled the various personality type letters. Very cool.

Sounds like a genre Gravity Falls would fall under.

So this map is actually a bit of an anomaly for me since I'm running it through photoshop to add color and other effects. Normally I hand draw them and leave them in that state.
As for where I write the information down, I literally just use a google docs file. Nothing but bulleted lists.

Personally I draw maps. From there I can work out what kind of people live where, what trade routes might exist, things like that. After that it's just a thing of populating the world slowly.
As an example, here is the world I'm currently working on.

You're looking amazing!
It's crazy thinking back to the last time I saw you in person and how much of a difference there is.
You look so much more happier now.

So yeah. That's two mental/physical diseases in one. I've got a few others that both alien races can come down with as well but only one of them is likely to come up in the story unlike Xenomadria which takes up a good chunk of the second half of the story which goes more into horror tropes.

Instead of the memetic infohazard developing correctly, instead the afflicted suffer a neurological backlash as their minds resist the parasite’s memetic infection and antimemetic cloaking."

Yes, I'm going full SCP style infohazard memetics warfare.

There is also a side effect disease called "Vethril Syndrome" which is "what occurs when a Saurathi individual who is naturally immune to Xenomadria comes in contact with the microscopic parasite that causes the sickness.

The parasite is protected with the use of an antimemetic shield which ensures that it is unnoticed by the Saurathi people."

"Xenomadria is spread by a microscopic parasitic organism which implants xenophobic, violent memetic patterns into the host’s mind, feeding upon the brainwaves created by these thoughts to allow it to spread further.

In truth the disease is an "engineered biological and infohazard plague weapon created by the Veilith" - another alien species that serves as the antagonists of the story working to sour human/Saurathi relationships.

"The cause of Xenomadria is unknown. Theories suggest that a neural effecting parasite of some kind is to blame which remains unproven as the disease has been known to go through conventional disease blocking barriers and seals."

where mental health professionals work closely with affected individuals to address their underlying fears and anxieties, promote understanding, and develop coping mechanisms to the initial stages of the disease."

"Treating Xenomadria is an immense challenge due to the severe and deeply entrenching nature of the disease. The treatment regiment requires a comprehensive approach that combines therapy, medication, and specialized rehabilitation programs

Translated out the name of it is "Xoenaomãdiria" or "Xenomadria", it is an "extremely rare and severe mental disease characterized by intense and irrational fear, paranoia, and xenophobia towards all non-Saurathi beings."

While I don't have one for my fantasy world setting I'm building yet, my scifi story has several that effect the alien race; the Saurathi.
To quote from my master design document:

Personally I think Nami is overdrawn, but I certainly am not saying no to more of Wanda!

Oh to be in his position.