I, too have Fibromyalgia, I was diagnosed about a year and a half ago. I found that having the diagnosis was scary at first but then I was grateful that I had a diagnosis because I was 'in the dark' not knowing why I had all of these symptoms for so long.
A couple of books that may be helpful on Fibromyalgia:
By Shelly Bolton, Fibromyalgia, A Guide to Understanding the Journey
I have communicated with Shelly via email and I contributed to the book. It is on Kindle and it is very helpful. Shelly has Fibromyalgia too, I'm pretty sure and it is good to hear a book from a perspective of someone who knows about it first hand.
By Roland Staud and Christine Adamec, Fibromyalgia for Dummies
This is a book that I picked up at a B & N the morning before I was diagnosed with Fibromyalgia. I had a pretty good feeling that I was going to be diagnosed, I looked at the book, came back to the store after seeing my doctor and getting the diagnosis, and bought it. For me, this is more of a basic manual for FAQS about Fibromyalgia, what it is and some helpful tips on how to manage it.
I can only imagine what you are going through right now regarding the new diagnosis. I have also heard from multiple rheumatologists that losing weight and exercise is very important in managing the condition of Fibromyalgia. It is an ongoing battle for me with managing my weight, I empathize with you. You're not alone in your struggle and I hope that you find the support you need.