Try this little test on yourself. Take 1000 mg. of vitamin B5 daily. Keep it up for a week or so. If you start to feel better that is an indication that you probably have adrenal fatigue. B5 is specific for the problem. I have been taking it for one year and have seen slow and steady progress and my life is close to normal. Last year at this time I would get waves of fatigue so profound that I could not walk across a room and the prospect of having to climb stairs filled me with dread. Anyway, there are no side effects with B5 so it is worth a try.
Adrenals are a mystery to most doctors. Sounds like that except for the thyroid nodules, perhaps your hormone health has not been addressed.
Low adrenal symptoms include fatigue, dark skin tone, weight loss, low blood pressure, poor healing, salt craving - in general.
High adrenal symptoms include fatigue, weight gain, high blood pressure, thyroid issues, poor healing, glucose issues, in general.
Symptoms overlap, and are not perfect, for instance, you can have low blood pressure with high cortisol.
In the case of fibro, I was diagnosed with that with my Cushing's (high cortisol) as the changes of cortisol creates a lot of pain. An endocrinologist should test you, and it does sometimes take an effort as most endos treat diabetes and thyroid (the latter being iffy in quality IMHO).
I would look up Addison's and Cushing's to see what fits, and see if any tests you have had in the past fit (thryoid abnormalities, androgens, vitamins) and see if that compels the doctor to test you.