What Is The Sharp Pain On Top Of My Foot?

I have sharp pains on the top of my right foot, from the 3rd toe down and on the bottom. It just started about a week ago. Went away for 3 days and now it is back and much worse. My right foot feels like I have hurt it, but I have not done anything or hurt myself. It really hurts more at night time or when I am active. I have Fibromyalia and may have lupas.