Thyroid & other concerns

Hi,
I was tested recently for an enlarged thyroid.  I believe this is a congenital condition since I've had a slightly enlarged thyroid from youth and was tested then for possible thyroid issues, all reports normal.  Anyway, my current results came back with the latest impression: Possible early diffuse disease. What does this mean?  What actually prompted my Dr. visit is that I've been having unexplained "fainting" episodes, the latest one in Sept. '08, a previous one on April '07.  I recall with this latest one, onset intense nausea, cramps, dizziness, heat flash on the back of my neck & chest, weakness and starry vision as to blacking out.  I was at home when this happened, it was 3 AM, I awoke to go to the bathroom after eating a late dinner.  In all, I stumbled into the bathroom and ended up on the bathroom floor taking shallow breaths and laying still for approx. 30 minutes until this horrible feeling went away.  I drank some water and eased into back into bed that night, with my family praying for me.  My complaints include sensitivity to cold, swollen/tender neck glands under the ears, occasional dizziness, lightheadedness, nausea, fullness in ears esp. when exercising.   I'm in my late 20's and no, I am NOT pregnant!  Any info. on what this could be?