I just found out I have lupus and fibromyalgia. Will I die with it or from it?

Lupus. With good followup by endocrinologist & pcp, and with good control of symptoms, you are ok.
Maybe. Without knowing the details one cannot say. It is unlikely that you will die from either one of the illnesses, but if they are nor treated and put into remission you may still have these when you die.