Can’t get a diagnosis!!

I have had a muscular type pain in the back of my upper legs, buttocks and lower back for about a year and a half. Had MRI- bit of osteoarthritis but nothing that should give me a muscular and tightness in this area.
Also having swelling in feet, ankles lower legs and lots of fluid around lungs, liver. Dr has me on a high dose of dieuretic but doesn’t know where it’s coming from. Also have enlarged lymph nodes in between my lungs. Had biopsies- no cancer cells. But drs don’t know why either. Pulmonologist thinks maybe sarcoidosis. I do have A fib and will probably be having an ablation in the near future. I am so frustrated! Been to primary internal dr, gastroenterologist, rheumatologist, cardiologist and pulmonologist and no one can figure me out. Any help or suggestions would be appreciated more than you know! Thank you!