Have you discussed this with a doctor? Had any basic tests? I would definitely do this if you haven't. I would have your adrenals tested particularly. I have had the same thing, and it's been called chronic fatigue syndrome, with several associated problems.
Here is a link to the site we created after I did months of research and created a health plan for myself. I posted the info so I could share what took me years to figure out, as well as the newer info I recently added into my process. The purpose is to give you a leg up on doing your own research into your unique path to wellness.
I wish you the best!