Please, if you can, visit a really excellent holistic practitioner who actually looks at the body as a whole functioning unit. Western medicine does NOT know how to do this. In this country, doctors look at each symptom and system of the body as separate things. Many people HAVE found relief (if this really is long-haul Covid related) by treating the nervous system with chiropractic care, naturopathic care and vagal nerve "re-set". They are treating the ROOT CAUSE of long-haulers syndrome. The body just gets thrown completely out of whack with Covid, which is why symptoms appear in a myriad of ways. I healed myself 85% with heavy supplementation. And yes, my blood tests etc. all came back normal too. I wish you ALL the very best!