I haven't been feeling right for the past month or so. It started with just being extremely tired all the time. Then I started feeling a little "off" -- you know, one of those days where you feel like you need an extra cup of joe? In the last two weeks, I have become so foggy brained that I feel like I am dreaming. I can't seem to concentrate or remember things; I just don't feel as sharp as I usually do. I have had a sinus-type headache in the last several days and have been waking up congested. I tried some Claritin this am, just in case it is allergies, but no relief. It is really starting to freak me out -- I sometimes feel like I can't even function, like I will faint if I exert myself too much. My neck has been very stiff in the last week or two as well. I have also been very thirsty and feel dehydrated no matter how much I drink. All of these symptoms have been worsening and I am really starting to get concerned!

I just went to my doctor and have no elevated white blood cells, my blood sugar is normal, blood pressure is low (normal for me). We are awaiting results from Thyroid test and he would like to do a CT scan. Any ideas about other possible causes?