Muscle tone wasting away

hi im graham, 28 years old, my muscles have been wasting for ten years, i had a brain mri but it came back clear, please does anyone know what part of my body i shud get an mri scan on cause i cant afford a full body mri, at least 3 quarters of my muscle tone has wasted away, im turning into a cripple and my family are so nasty to me, they think im mad, please, how can i diagnose horrible muscle wasting disease, my body is twitching everywere its destroying me ;(