It's normal to feel horrible in the first few weeks of the SCD diet. If the symptoms are too much, do a slower wean off of the illegals. After you get through the die-off phase you'll start to feel so much better. I have been doing SCD for about 9 years and I think it's kept me from biologics and long-term antibiotics. However, with that said, I don't know if it will help the pouchitis while you're already in a flare.
Also, it really helps to understand the science behind the diet and why the strictness of it all is so important.
It's not a miracle cure and it can take a while to see improvement, but overall I think it's been great for my pouch function. I did feel significantly better and have had long stretches with no pouch symptoms whatsoever. (I have not been entirely problem free though!)