I was diagnosed with fibromyalgia last fall. As with you, I have been very active since I was 25 and I'm 54 now. I have had a never ending series of immune/inflammatory symptoms on and off for my entire adult life, along with several weird symptoms that no one has ever figured out.
I've been on the tricyclic anti depressant on and off for a few months. It helped initially and then I stopped for awhile.
What really has helped me is acupuncture, PT, and yoga. Make sure you find an acupuncturist who has experience with fibromyalgia. The PT has "cured" me of a whole set of problems that I was just enduring while cycling. I now have exercises I do 6 days a week. Again, make sure you find someone who knows about cycling.
I don't really like yoga, either, especially the "spiritual" aspect. In fact, some of it seems silly to me. But, it did help. I do most of it at home now, with yoga that is specifically designed for cyclists. I supplement it with a class at the gym once in awhile.
And don't let the MDs tell you to "take it easy." I know I have to rest more at times, but when my doctor told me to "ride 5 miles instead of 50," I laughed and told him it was five miles just to get to the end of my street!