Hello and Welcome to NeuroTalk. I also suffer from FM and the Rheumy says I have PM also. It's a day to day thing, never knowing how your'e gonna feel. But, your'e right, one step at a time and one day at a time.
I don't have any knowledge as to how young one has to be to be DX'd w/FM, as I was DX'd well into my adulthood. *yup, I'm old*
Please take a look around and make yourself at home.