I don't know if this is of any help, but is the backslide due to B supplements? Or is it more the result of the "natural" rollercoaster of chronic issues?
I ask because multiple times I have had the feeling that certain remedies caused a backslide, but in reality it turned out they didn't.
Maybe it's just my experience but often times, not always, it is pretty difficult to discriminate if an improvement or a backslide was caused by a specific product or it's just the natural course of the illness.
Our minds are eager to find causal links between what we do and what happens but the variables often times are too many. That's part of the placebo problem too. Did I get better because I started taking product XYZ or could I have gotten better even without it?
Sure when you start something and it works (for good or bad) and the effects go away when you stop, multiple times, then there's little space for placebo.
Hope it makes sense.