Whew. Never thought I'd say "Praise the Lord it was just the fibromyalgia!". I am glad it was something you could see a doctor for and have treated as opposed to what I was thinking!
I am also glad you have the eyes to see all the blessings taking place in your life and yes, although you do not feel "worthy" right of doing His work right now, God WILL use you to help others.
I'll keep checking on you. You keep fighting the good fight.