I seem to be helped by whey too. I've been taking around 100g (25×4) a day since april, and it seemed like an immediate improvement, that has lasted. Though April is the time of year I've gotten suddenly better in the past too, so I can't be sure if it's the whey.
I was the worst I've been this winter, could hardly walk or talk. Now I can manage short walks or doing light house chores if pacing carefully.
My cognetive symptoms are not better however, so I feel like a zombie walking around unable to think. The cognitive symtpoms have always been the worst for me though. I've been overdoing it too, when finally having a tiny bit of energy, and that's probably making my cognetive symtpoms worse.
Hypoglycemic symptoms are much better. I eat a low carb, high protein diet, and try to do as low histamine as possible.
Digestion is better, no idea if it correlates.
I haven't had an appetite in forever, but when I started the protein powder I began craving it all the time. And it's not because the taste is so good - I just use a plain one in water.
So far it seems like the thing that's made the biggest difference out of everything I've tried, and I can't imagine ever stopping using it.