Trying to explain the unexplainable.

I've just managed a shower. Looked in mirror and to all outwards appearance I look a healthy middle aged crone.  I don't blame people for disbelieving fibro.  It's really difficult to understand that inside that outwards look I'm struggling to move, that each movement feels like agony, that I've no energy left after showering to towel myself dry so I just wrap myself up and drip dry flat out on bed.  Again.  Head hurts, bones feel like they're full of flu, skin is crawling with unseen ants and I've got freezing feet even though I've got thick fleece socks on.  But none of it can be seen by the onlooker so they think we are pulling their leg. 
I'm not after sympathy but asking you to just try to understand.