I wonder if you would benefit from Aggressive Rest Therapy (ART) - we're just talking about it in my thread on pacing
here. You essentially force yourself to rest for periods of time when you're feeling like you don't need extra rest, so that you can consolidate your health and use the extra energy for repair/healing.
It seems to be an area of active debate, but there have been a few reports where it helped people improve permanently in the past. It might be useful to build some more regenerative capacity considering your up and down pseudo remissions.