Yes, I very much relate to this. I am a student and this same thing happens as soon as I am home from a single class. Doesn’t matter if I slept 8-10 hours (I normally do). My arms get so heavy, sometimes I’m scared to even drive home. It seems to be getting worse. People tell me to work out to strengthen or focus on my gut health, and I’m trying but literally have zero energy to do those things well. The best I can do is walk outside once or twice a week. Anyway, hope you can relate to this some. I’m just starting this journey so really have no good advice to give. Epsom salt baths help me with muscle pain and tightness, that’s about it.