Hello, I feel for you. I’m a 77 year age woman. I was diagnosed with SLE about 4 or 5 years ago, plus Hashimoto’s. Men, as well as women can have SLE; so have you been tested? The various symptoms could very well be SLE as I experience them as well. For the never understood symptoms I found that Zyrtec almost always cures the itch at that time. I, too, was athletic and suddenly I became weak. At times I know I should eat but I’m not hungry. I eat no meats. Only seafood as in 1993 it was determined I was allergic to all meat, including eggs. My horrible rashes were on my legs ultimately after huge red itchy areas were diagnosed as “eczema” meaning, nobody knows what is causing it and always was placed on prednisone or antibiotics and given a steroid topical cream. Which did not help. I’ve scars from scratching so much. But the leg rash went away after the diagnoses and I can no longer have gluten, dairy, wheat, no cruciferous vegetables or anything from the nightshade family. I’m sure I’m forgetting something.
After being diagnosed, I told my doctor to just treat my symptoms as had been done by various doctors in the past.
Nobody believed I had SLE as no rash on my face. My cousin has discoid lupus. Her face looked like my legs with the horrible itching, etc. I believe I have had or have sjorgen (everything is very dry). I’ve had some rare eye issues as well that were autoimmune related and have always been told all these may come back. I had Graves about 15 years ago. It was bad enough I took propanol for a year. I was told it was in remission. I could go on.

I would suggest being tested for autoimmune issues, and I hope this has helped.