One of my friends on my expat forum has Pernicious Anaemia, which (since it is also an autoimmune disease) has almost identical symptoms to MS. So many that I originally thought that I had PA, and asked the doctors to test for it. We've been messaging a lot and she sent me this:
http://www.butyoudontlooksick.com/articles/personal-essays/the-spoon-theory-written-by-christine-miserandino/ The spoon theory. The girl writing it has Lupus, so the symptoms are different, but it still sums up my bad days pretty well. Especially the bit where standing on the train costs 1 spoon. I think it might even be more than that...