Hi Mary, welcome to the forum. My mother has fibromyalgia too and actually uses exercise for pain management. She even set up an exercise room in her house. I know that some days everything hurts, but you might be much better off talking to your doctor about what you can do for a work out and getting a regimen started, even a small one can be very beneficial.
As for lunches, I do salad maybe 50% of the time, but I vary the toppings, garden, cobb, taco, etc etc. You can also make a decent variety of sandwiches, egg salad, tuna salad, chicken salad, low-fat low-cal cold cuts with reduced fat cheese. Then you can vary the bread, I usually use low-fat, low-cal, whole grain bread, slim buns, slim bagels, pita bread, English muffins or tortillas. I also like cottage cheese with stuff to dip in it, like veggies or fruit. Greek yogurt is a tasty lunch option too, and it's really good with some fruit or sugar-free jam stirred in. Some of the "healthy" canned soups are nice for lunch too, especially if you have a microwave at work. I frequently heat up leftovers for lunch, and since I make a healthy dinner for the whole family it's all good.