Do I have and autoImmune problem? I have increasing fatigue and joint pain. but neg lupus and rheumatoid tests?

I am 40 yrs old and over the past year or so have increasing severe fatigue, pain and aching in my back, neck, hips and shoulders. I now have about 10 "good" days out of each month. I also have been sick a lot, have had reoccurring shingles. I get hives out in the sun and burn in only a few minutes. And I get weird rashes on my body -usually down my back or my upper neck and chest area. I have low thyroid (but levels are in control with low dose of med) and occasional anemia. I am a healthy weight, healthy diet, and very active but now if I push myself too much with activity I get extremely nauseated. Rheumatoid and Lupus tests came back negative but my Igg (?) was low. Also a few weak positives. My doctor is trying to get me referred to a rheumatologist or immunologist but it has been months going through the hoops with poor medical insurance provider and still trying. Maybe a change in my diet could help if I knew what was wrong? I'm becoming more frustrated by the day.I have 4 months of nursing school left and have got to get better to make it through and finish! Any ideas whats wrong with me? Any thoughts or suggestions would be appreciated.