This might be a failed experiment and not the end of your search for a diet that suits you. As for losing weight
, it is a long, slow process when it works -- quick weight
loss usually is temporary, whereas loss from a permanent change in lifestyle takes time but lasts. I have no idea what's going on, but have you had your thyroid checked? I'm sure you have, but it sounds a lot more like that than fibromyalgia, at least from the little you've detailed here.