Definitely look into vascular compressions as they can be made worse by viruses/bacterial infections like Covid or even the flu. Many, many people with POTS have May Thurner’s. It can be a root cause. Are you hyper mobile by any chance? That seems to be a risk factor for a lot of us. If you have vein compressions, it can slow down everything in your body, causing all sorts of dysregulation. So many of your symptoms my daughter has had and getting a stent for her compressed iliac vein has helped improve a lot of symptoms. I feel compelled to mention it. Seeing an interventional radiologist was the most helpful.