Gentle exercises like walking give me more energy. Also I take vitamin D3 and malic acid/magnesium supplements and they help with pain and fatigue, too.
Be sure to be on a sleep schedule and get your rest each night. I know that can be a challenge with fibro but you can get enough rest
Lastly, don't eat too many carbs or sugary things. That will boost your blood sugar and then it will plummet and make you feel washed out. Eat things like veggies and also high protein food.
Hope this helps.
Sherrine