I feel for you . . . Truly. It looks like you are putting up a valiant fight, and that you are considering serrapeptase is a sign that you are already thinking outside the box for deeper solutions. I no longer take serrapeptase, but when I did, I was also taking other proteolytic enzymes, and consistently, I took each enzyme separately so that I could control and modulate dosing across these. So I never tried the Enzymedica product, but I see that it contains 40,000 serrapeptase units per dose, which, for me, was my starting dose. (I found that when I increased up to 120,000 units/day, I developed bronchospasms (my manifestation of a mild chronic asthma. Serrapeptase can actually help some users with lung congestion and spasms, but in others, it can bring on an annoying cough that feels like cough-reflex asthma.) I used many different brands of serrapeptase. All were claimed to be acid-resistant, and most achieved this through an enteric coating. I took the word of each manufacturer, regarding acid resistance, but never really dug deeper to see whether the particular product had been conclusively shown to make it intact through the upper GI tract.

Iĺl digress now to say that while on serrapeptase, I did initially see a really noticeable improvement in the number of hours, each day, I could breathe better through my nose, but the cough got to me in the end, and I pared down my whole regimen. Now I am relying wholly on a long-term B1/thiamine protocol in hopes of reversing the vasomotor rhinitis with nasal block that COVID left me with, and patience may be paying off, because even without the large collection of sinus-focused remedies (enzymes, Chinese herbs, Western herbs) that I took for my initial months after COVID, I am seeing improvement now that is gradual, but more steady than what I experienced before I committed to significantly higher doses of thiamine daily. If you haven´t looked into thiamine supplementation/repletion for the chronic disorders you are experiencing, please consider doing that. Even PCOS has been found to be associated with dysautonomia, and if you follow this lead, you may discover that possibly all disorders you had even before COVID hit have been linked to thiamine deficiencies or thiamine metabolism defects. The pioneer in this field was Dr. Derrick Lonsdale. His textbook is a very heavy read, but lots of his shorter scientific and popular-audience articles are easy to find just by Googling, and you may find these quite interesting. The theme in all of Lonsdaleś work was that the deepest cause of a very wide range of modern human disease is disruption of a wide range of our molecular-level metabolic pathways, and that this disruption, in turn, is the result of basic vitamin deficiencies and malabsorption syndromes that make it impossible for our natural healing pathways to work properly. (He focused on excessive refined carbohydrate consumption in the modern diet of developed countries as a likely trigger of metabolic pathway disruptions.) The clinician who has made Lonsdaleś work most accessible, in my view, is Elliot Overton, a functional medicine practitioner in the UK. His materials are available online, too. Please hold on to hope. You are young, still. I am lots, lots older, and even I am starting to see light at the end of the tunnel as I continue with my thiamine protocol.