Overwhelming fatigue, constant nausea, short of breath on exertion

I got Covid last Thanksgiving. For months I slept 16-20 hours a day. Now a more manageable 8-12 but I am exhausted. I can only do simple tasks due to the shortness of breath (sob) which is s l o w l y improving. I’ve been going to physical therapy (PT) 3x/week for months. I did not lose my sense of smell but have constant nausea. Most things taste terrible & mostly I prefer cold food. I’ve lost 35 lbs. Probiotics made me twice as nauseous. I have physicians who are internal medicine, pulmonary, neuro, GI, psych & rheumotology. My physical therapist is the only person who seems to understand how debilitating this is. Any thoughts or suggestions would be appreciated.