Hello Vandermolen, I believe you, completely. I dont like to give this advice, but I am going to:
I believe, dry skin, thinner epithelium layer, breaking apart mucus membranes, these are halmarks (to me) for POIS. Sjogrens has same symptoms. Chances are your doc will suspect Sjogrens, however upon advanced testing (i.e. anti-bodies), Sjogrens will be ruled out. I believe, our thinner epithelium is also the cause for POIS, skin and brain symptoms - skin symptoms being, dry eyes - I used to even get growth under eyelids, dry esophagus (making me susceptible to sore-throat, various allergies), weaker muscles, etc. And brain symptoms being brainfog, emotional state, anxiety, speech, etc.
I am mostly POIS free now, and trying to get off the too many supplements I take. I believe, you have to do 2 things:
a) change your diet. Eat high-fat (healthy fats - plenty of them), and simultaneously reduce your Carbs to minimum.
b) take 'growth' supplements to help your mucus membranes heal, gut lining grow/heal, epithelium to thicken.
c) resolve your digestion issues. Betaine HCL, Digestion enzymes, Bile Salts (purified).
I do not think Sjogren's is at all like POIS. I hade POIS 25 years and Sjogren's 5 years. I never had dryness before 5 years ago. The only symptom similar is the fatigue. But POIS fatigue is caused after Orgasm and Sjogren's is all the time.