Nausea, abdominal pain, and weight loss are hallmark symptoms for adrenal insufficiency. There are of course many causes of nausea, but adrenal problems are not something that most doctors assoc. with nausea right away. Aching muscles happens with low cortisol from adrenal problems, it can be very painful. I had horrible nausea for months, lost wt. and all the docs blamed the nausea on lyme, but it turned out to be adrenal failure.
Also In my experience my muscle cramps have been caused by toxins, low potassium and hypothyroid.
Other symptoms of adrenal problems may include imbalance in electrolytes (sodium & Potassium).
How are your sodium and potassium levels?
Have you had your cortisol or aldosterone level checked? (both are produced by adrenals)
Have you had ACTH level checked?
Have you had your thyroid tested? FreeT3, FreeT4, & TSH?