As I understand it, ME stands for myalgic encephalomyelitis or sometimes also myalgic encephalopathy. It is the more common term in Great Britain, but is used to refer to the same illness that people usually call CFS in the US. The terminology chosen can be a hot political topic in the ME/CFS community, but basically they all are often used interchangeably.
Myalgic - means muscle - indicating the pain involved in the muscles.
Encephalo - means brain - indicating that the brain functioning is involved.
myelitis - means inflammation of the spinal cord and does not occur in M.E. so 'pathy' ( Myalgic Encephalopathy ) is now being used instead which means 'sickness' or 'illness'.
"Don't be afraid."