Could fibromyalgia cause pain in the whole leg like a bad fatigue but in the left leg more than right. Please I suffer severe pain in the whole leg?

Doubtful. This does not sound like fibromyalgia to me. You should really see a doctor and preferably one that deals with pain issues.
Not likely FMS? I have never seen pain in one entire leg with fms. I would worry more about a disc, piriformis syndrome, or phlebitis. They are quite common and should be excluded.