Dizzy and migraines

I have recently been undergoing tests for migraine headaches and dizziness.  I have had these symptoms for at least ten years, but they have worsened over the last year.  I experience 3-4 headaches/migraines a month.  Daily I experience tingling in my fingers and my head.  I have noticed when I get hot or am in the sun my dizziness increases dramatically.  I cannot go into tanning beds because of the dizziness and feeling as though I'm going to pass out as soon as I get out.  My vision has become blurred during headaches as well as without them.  I had an MRI and the results returned all is normal.  I experience noise level changes in my hearing as well.  I am very lost as to what can be causing these symptoms.