The most important thing with any form of exercise (when having FMS/CFS) is to pace yourself and not overdo it. Low-impact is the best form of therapy for us.
I don't feel you should quit because it is probably beneficial to your body. Try not doing the ones that are difficult and stick with the easier movements...maybe lessen the time a bit also.
Take care and be safe.
Hi, a lot of the yoga moves bothered me also. What I do is just the breathing and the simple moves that don't hurt my back. I pick and choose.