Hi can any one help me with this, my legs feel so achy and weak to stand on, not like when you are well and go to the gym! This is awful, i do notice it is worse premenstrally. I am low in iron and ferritin? Earlier on at the sink i thought i was going to drop with the feeling in them. What is this can someone explain i also was diagnosed with m.e in 1999, but this symptoms is different? is it anxiety. (jelly legs)