Talk to her. Communication is key. To understand fibro, just imagine how you feel when you have a very bad cold, and now imagine having that every day of your life. Also imagine how you feel when you wake up in the mornings after only having slept for 2-3 hours everyday for week. We might be able to sleep 5-8 hours a night, but we wake up feeling unrefreshed/exhausted even before our days begins. Fibro also not only affects the body, but the burden is so high that mentally it also makes life very hard to cope with.
Your wife is lucky to have a loving husband like you. I'd advise you to read about fibromyalgia as much as possible, maybe look for other family members/husbands online who have fibro sufferers in their families. I know it must be very hard for you too. Not because this is happening to a person you love, but also because living with a sick person day in day out has an emotional toll on all family members and their identity as well. So do not forget to think about your own well-being.