My thoughts: You are battling an autoimmune disorder. It is possible to have psoriatic arthritis without having psoriasis. Whether it is PsA or RA, it is likely that you had a “flare” on your terrible flight that created a “cytokine storm”.
From Cleveland Clinic on cytokines:
“Cytokines are signaling proteins that help control inflammation in your body. They allow your immune system to mount a defense if germs or other substances that can make you sick enter your body. Too many cytokines can lead to excess inflammation and conditions like autoimmune diseases.”

The question is how to calm down the cytokines. My symptoms have been similar and I have made great progress with anthocyanins that are in deep colored fruit and veggies. They are in blueberries, black beans, red cabbage, red onion, black rice, black raspberries, red or black grapes, black lentils, purple carrots, grape juice and wine. You have to “hunt” the produce department. Anthocyanins are fragile so they are best fresh or frozen without cooking.
You are very active and may not have the time to make your own food. It helps that I am retired. It is best to get anthocyanins from food, but there are supplements like bilberry extract that is grown in Finland. Bilberries look like blueberries but are blue throughout that gives them high anthocyanins.

Here is a link to a Cleveland Clinic article on anthocyanins:
https://health.clevelandclinic.org/anthocyanins