Crazy, you were a doctor and aren't sure what the issue is? That saddens me. :(
Have you had a sleep study? They can tell a lot from that.
Have you had your thyroid and adrenals checked out?
I can't stress enough the importance of looking online for a high dose, high nutrient, multi-mineral & multi-vitamin, supplement. Something with many good testimonial reviews for conditions helped.
VERY important for energy and handling stress is Magnesium and the B Complex Vitamins. Magnesium/Calcium/Vit D are especially indicated for muscle and joint pains and problems.
Some of the safer and more effective forms of magnesium include: Taurate, Glycinate and Citrate (latter can be laxitative, so take with food).
Kelp is the richest dietary source of magnesium that I've seen thus far.
FANTASTIC information below:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2146789/pdf/canfamphys00077-0094.pdf
http://www.medhelp.org/posts/Neurology/Muscle-Twitches-All-OVER/show/295459
"Magnesium: The Stress Reliever" by Leo Galland M.D., F.A.C.N. (online article)
"The Importance of Magnesium to Human Nutrition" by Michael Schachter M.D., F.A.C.A.M (online article)
"Magnificent Magnesium" by Priscilla Slagle M.D.
http://www.thewayup.com/newsletters/081501.htm