Treatment For Weakness, Thigh Pain And Lower Back Pain

i am 26yrs old female, for the past one month suffering from calf,thigh and lower back pain more at night and more weakness and unable to walk sit even to lie. doctors tested EDTA whole blood test, lumbar spinal mri test , obdomonial and pelvis ultrasonography, complete urine test (except epithelial is 6-8/hpf), total stimulatin hormone (tsh), bp 100/69, electro-nerve conduction,ECG, creatinine kinase (cpk), calcium, sodium,potassium, all are ok.