Hello damians,
Welcome to a wonderful group of people who will take time to be there for you and support you in any way they can.
I was curious as to the symptoms you had when you had your viral infection. The things you mention sure sound pleurisy-like to me. It's an old friend of mine, and I know the pain it can cause. Just an idea for you to look into.
I obviously can't give you a diagnosis of any type, but some of the things you speak of yes "could" be fibro related or could be the lingering symptoms of your viral infection. It could also be some type of arthritis. The only person who will be able to help you in this is a doctor, preferably a rheumatologist.
If you have had gastro tests and so on and they have discounted this as being the cause, then a doctor would be able to tell you if in fact you are having the intense muscle problems that can occur with fibro that would cause such tenderness.
Take care and hope to hear from you again soon.
goldenwings