My vitamin d level is normal. I live in a hot climate with lots of sun and I have to walk to the bus.

I feel like my body's dead weight I also loose my balance had a couple of trip and falls and the fatigue is terrible also brain fog

Yes most certainly! In fact most movements I make feel like I am slogging through mud up to my neck. It feels like pounds have been added to every limb. I haven’t found a way around this symptom.

i also struggle with stairs every time i have to walk up more than a couple my legs feel like they will buckle

I have a very difficult time with stairs. My husband helps me. I am very weak and unstable, so I take them very slowly, so I won't fall.