Sorry to hear you are going through another bout. I seem to be the extremely fortunate as I have not had a recurrence in over four years now.
I know this is completely off beat, but along the lines of diet, I have be trying to juice as much as I can. It is a pain to keep the juicer clean and to make the juices, but I have to admit that I feel better when I do. I know it is likely only a placebo affect that I am feeling, but I will take it!!
When I was first sick, a friend referred me to the movie and web site http://www.fatsickandnearlydead.com. It is about an Australian with an auto-immune who juices and travels his way across America. Not sure the science is sound, but again, when you are feeling that crappy, you will try just about anything, and so I did.
My favorite juice is as follows: Kale, spinach, and Swiss chard with an apple, half a lemon, and some strawberries all over ice. It is green and gross looking, but tastes not half bad. I just visualize all those good ingredients running like an army to help my immune system!!
Lastly, I took the 23andMe.com test. It is very cool. They now have over a million people in their data base and are trying to help pharma companies find enough people with wierd stuff like we do to sift through our DNA to find cures. I think all of us with this auto-immune should take the test, then tell them we have, who we are, and try to get a scientist to start looking at our DNA for a genetic marker. Just a thought.