You are smart to have that attitude. I wish I had it 10 yrs earlier. I just trusted my doctor who said tests results looked good and started implying that it was psychological. I had no history of psychological problems.
My wake up call was a broken leg without *any* contact while just playing badminton with little nieces! Psychological problems don't cause bone density problems in a 42 yr old male! More on that here. //www.curezone.org/forums/fm.asp?i=1951581
You have much to learn about thyroid, adrenals, amino acids, neurotransmitters, maybe chronic exposure to heavy metals, digestive tract imbalances, etc.
In addition to the links at my curezone link above, you might also check out the book by Dr Daniel Amen, Change Your Brain, Change Your Body. You'll learn how neurotransmitter imbalances can cause or contribute to weight gain as well as mood problems.
Look especially for problems that can cause a symptom cluster that matches your situation!
For example, low magnesium can be related to poor stress tolerance, some depression, poor sleep, constipation and muscle issues, poor energy production, etc.
Is low stomach acid causing you to fail to absorb normal amounts of a mineral used to darken hair, another mineral or amino acid used in your immune system and amino acids used for neurotransmitter production, etc.
This gets complex but the books by Dr Amen and Andy Cutler help you with the detective work. You can then take your suspicions back to your natural or functional medicine doctor (not an HMO doctor!)