I had a bout of irregular heartbeats toward the end of last year. Even went to the ED because they were so strong. I seemed to think it was far more urgent than the ED staff did, but c'est la vie (err, um, find another phrase, Steve). EKG, chest X-ray, Holter monitor for a week; nothing (and I purposely stressed myself while wearing the Holter). They think it was brought on by dehydration and exertion so soon after I had the flu that went around this winter. No symptoms since. The occasional loud heartbeat that seems "off" but nothing strung together over time like that event.
A relative of ours has fibro and a bunch of other medical issues that make her life a daily slog through however many "spoons" she has that day. I can't imagine living with that on a daily basis; being my age comes with more than enough reminders of joint aches and running out of energy. Toward the end of last year our relative noticed a further deterioration in her health; in her case it turned out to be related to a disease she'd had in childhood and she is recouping that deterioration with additional medication.
It took her months to find doctors who would look at the new issues and not just chalk it up to existing conditions (including her existing medical team). Her experience mirrored yours; almost all doctors nowadays are specialists (even "microspecialists" like "heart hydraulics" or "left ventricle") and no one but the patient and the rare general practitioner connects all the dots into a drawing that resembles ... what?? Medicine is a business; probably everywhere, but particularly so in the United States where profit is king (even for ostensibly non-profit health organizations). I do not believe that will change in our lifetimes and perhaps not even our childrens' lifetimes. That might be less of an issue if the quality of our health care was unparalleled in the world but key indicators show that we collectively pay lots of money for mediocre outcomes.
For what it's worth, I don't fear death. I fear pain. I'm not sure what steps I would take to avoid severe or constant pain. I do sympathize with your situation, though, CathyA, and hope someone has a breakthrough for you.