As a nurses’s assistant that has fibro- Do NOT take the no flush Niacin- this builds up fast in the liver and you can end up with jaundice quite unexpectedly. The regular ol lobster flush is uncomfortable but very good for circulation, preventing migraines, regulating raynauds with icy feet, sleep quality improves, etc.
Regular flushing Niacin has been used for lowering high cholesterol levels, treating alcohol dependency/addictions.

The number 1 thing is listen to your body on what you can do with exercises. Walking is good .

I feel like the flush causes a flair up. Twice it has happen.

I've found a lot of my fatigue stems from insomnia, anxiety and my depression. The last two tend to cause the insomnia, or at least contribute to it and the lack of sleep agrivates the anxiety and depression further.

I've found melatonin helps just as much as the sleep aide(that also helps but is addictive and not natural) unisom. Both melatonin or unisom help me get a restful nights sleep which at least on average helps with the other two so it also helps with the fatigue.
If that doesn't work, I bite the bullet and drink coffee.

Agree with walking but only if my hips aren't tender. Some days they hurt like the devil. So hard to go walking.