I have trigeminal neuralgia and it is the worst pain I have ever had in my life. I haven't had a bout with it for a while, thank heaven. When it flares up I only eat things that are soft, no chewing, and then only when I'm really hungry. I apply hot and cold packs alternately and take muscle relaxers. As far as how it affects my fibro in general, anything that hurts that much just seems to make everything else hurt more too.
Hope this helps.