Marcy, you have so much going on and I am sorry your problems have not gotten someones full attention! Some connections and questions for you: did the cause of your CHF get figured out? The most likely guess is it could be a cardiomyopathy which is autoimmune. The atrial enlargement is likely due to the mitral regurg, since blood is leaking through that valve, flowing backwards into yhe left atrium. Of potentially more concern is the tricuspid regurgitation which could signal pulmonary arterial hypertension (PAH). These issues should all be addressed by the cardiologist. PAH is treatable and early detection and treatment is important, so you should get a lot of mileage out of the cardiologist consult. The POTS will also be addressed there.
I’m wondering if you could have a malabsorption issue (low calcium, potassium) if those are still a problem. Hashimotos is treatable also. Perhaps the cardiologist can help you get a good rheumatologist to deal with the possible SLE, likely causing the hyperpigmentation and perhaps nose sores. Keep in mind that I am speculating here and just trying to make sense of some of your concerns. Please keep us updated on your progress. I think you’re on the right track and on the brink of getting much needed help!