You sure you don't have sleep apnea? Try heavy doses of vitamin D? Like 4x daily recommended? Ice baths/wim Hoff breathing techniques? I feel for you, I'm just brain dumping all my tangential knowledge.
My most annoying symptom is when I exercise, sleep the day after and subsequent couple of nights (not the night of, strangely), is completely compromised. Really shallow, hot sweats, waking up multiple times etc. Im trying to understand if this is dysautonomia or PEM at the moment. Most of my fatigue follows from having this disrupted sleep I think and I dont have flu like symptoms typical of PEM, but it does feel like im having an allergic reaction. Very strange