Chronic neurological, thyroid, and sinus symtoms(symptoms), and now fever

I have been sick for 6 months with the following symptoms:
pain and tingling in extremities, twitching muscles, tremors, constipation, sinus pressure, insomnia, fatigue, eye pain, tachycardia, excessive sweating, chest pains, shortness of breath, tightness in chest, neck, and jaw, headaches, nausea, swollen gums, and now for the past 3 days I have had a fever that gets higher than 101 at night. I have been test for M.S. and related neurological disorders, B12 deficiency, diabetes, and some other things and the only thing that has shown up on tests is that I am slightly hypothyroid. My doctors cannot figure out what is wrong with me, but I am desperate to figure out what is going on. I am beginning to wonder if this is Hashimoto's or Mono. Does anyone have any suggestions?

[Red_Star]

I had most of your symptoms concurrently due to a severe magnesium deficiency.  I also have Hashimoto's as well; an under active thyroid can cause a magnesium deficiency  My magnesium deficiency worsened to severe after surgery and prolonged high doses of vitamin D.  Only 1% of magnesium is in the blood so a deficiency may be missed. That said, you can test for RBC (red blood cell) magnesium or ionized magnesium which can give a more accurate picture than serum magnesium.

Thyroid patients risk of reactivation of the Epstein Barr Virus.  The Epstein-Barr virus is thought to be responsible for glandular fever (otherwise known as infectious mononucleosis or mono).

Btw, if your B12 serum is under 800pg/mL or 600pmol/L you need to boost your levels. Symptoms are well known to occur in "normal" levels due to far too low a reference range.