Hi Mamabee!
Welcome! I hope you find some answers here! I'm 30 and was diagnosed with fibro last year. I have all the symptoms you mentioned in your 1st paragraph.
Often, fatigue is a result of mitochondrial dysfuction. That is true for me. Some supplements that have helped me with fatigue include D-Ribose and DHEA in low doses. Foods high in antioxidants help the body heal itself. I have also had success with aronia berries, which stimulate the body to produce its own glutathione.
There are a couple of environmental factors that can contribute to fatigue--mold and electromagnetic radiation are biggies. Mold produces neurotoxins. Depending on the type of mold, brain damage can be done. Mold can hide under sinks, in ductwork, on concrete slab, in carpets, and in walls. I found mold in 11 of 12 apartments in one college town. I've had some brain damage from mold. Electromagnetic radiation from cell towers, antennas, cell phones, wifi, and other electronic devices can also contribute to fatigue.
Formaldehyde in new carpets, houses, clothing, cars, etc. is a chemical contributor of fatigue. I am highly sensitive to formaldehyde, and cannot even wear new clothes without washing them first. Breathing it shuts down my lungs, likely because I have mycoplasmas.
My IBS is from Candida and leaky gut, which I've had for a number of years, due to being on too many antibiotics as a child. I'm starting a protocol for this with a nutritionist shortly.
Because of my leaky gut, I have a lot of malabsorption issues with foods and such. Even though I had been consuming minerals, I was not absorbing them. I found that using bath minerals has helped tremendously because I can absorb them through my skin, and that has strengthened my bones while decreasing my bone pain.
I also did a hair test and found that I had a lot of mercury. Detoxing from this with the help of my MD lifted my mood, fatigue, brain fog, foot pain, and TMJ pain. I still grind at night, but the pain is gone. For the first time, I can handle walking without orthotics. I haven't been able to do that in 12 years.
I'm not on any pain medication. My theory is if my body hurts, it's trying to tell me something--and believe me, I've had some severe pain (esp. ribs). I do have Hashimoto's and Adrenal fatigue, so I'm on prescriptions for those.
Has your husband tried a nightshade-free diet for his Ankylosing Spondylitis? It should reduce inflammation and pain. I get joint pain and burning eyes when I eat nightshades. If you do a search for Norman Childers you can read more about the relationship between nightshades and arthritic conditions. He's the pioneer in that area.
I hope you begin feeling better!