Man the way you describe this is very similar to me. I started about a year ago. My kids were sick about a week or so before this then passed the sickness to the other one, I however never got sick. Went for a run, came home and was fatigued beyond what I have ever felt. Muscles twitching randomly anywhere, high muscle tension randomly, stinging pain in random areas of my body, burning sensations in at times my dorsal forearms, face. Random vibration felling's in various muscles groups that would come and go. Thought I was dying. Went to the ER. Was covid negative and all tests normal. I had definitely gone through trauma recently as well about two years before (my mom passed from ALS). My hands felt weak and more jittery than before which then would get better and then somewhere else in my body will get that feeling. All I could think was I had a genetic link and had ALS. Im the youngest in a big family and none of my siblings had anything, even my mom never twitched at all during her progression. Saw neuro, did their scans, nothing showed up. Had very low Vit D and testosterone. started supplementing. Did an EMG. Due to my fatigue he did a test for Myasthenia gravis. Passed all tests thankfully. He thought It was a viral cause and to give it time. I spent many horrible anxiety filled nights after this researching, reading forums, super focused on my symptoms, hallmarks of health anxiety that I have. My highest Anxiety had the worst symptoms, but my symptoms were causing my anxiety. Horrible loop I slowly got better without even realizing I did. Months passed and the twitching went down significantly but never left. Happened very gradually. About 70-80%. Burning was gone, severity of twitching when it did happen was significantly less, no more vibrations, no more stinging pain. Never back to 100%, but started to be able to do more at the gym. Happened so gradually I thought "Maybe this was always in my head"? I am a chronic worrier afterall and always in my head. fast forward 10 months after. Im outside doing gardening, go to the gym, and BAM, a few days later im exactly in the same spot I was at my worst, with ALL the symptoms in the exact way they were. Crazy. I did have horrible brain fog. for a few days couldn't concentrate on anything, my anxiety filled my head again and I went back down the rabbit hole. Spent countless hours searching the web again for answers Until it hit me. Wouldn't you know it, both my kids were sick again during my second bout, I was not. Currently am slowly improving the second time like before. Its weird how similar the symptoms are between bouts. I remember lifting a weight at the gym and feeling horrible wrist pain, searched up carpal tunnel as a result but that got better without me realizing. When it happened again I felt that EXACT pain lifting a weight again for the first time today. Unsure if this is post viral Fatigue, BFS, Fibromyalgia, or anything else, but man its been tough. Would like an update on where your at now? you doing good? I know its years later, but this post hits too close to home me not to comment on it. Have a great day!