What Causes Dizziness, Fatigue And Severe Cramps In Legs?

Hello I have been close to fainting for a few weeks now, and friday I actually fainted. I thought I was going to throw up and fainted on the way to the bathroom. I ve been dizzy, nauseated and almost fainted again today. I have a dull headache, possible fever and stomach pain. Friday after I fainted, I also had a sharp pain in the pelvic left side area and a pulling sensation from there to in between my legs. What could be wrong. I also have intolerance to cold. Could this be from my hypothyroidism which I take levothyroxine for.? Thanks! Lee Ann