HbA1c is glycated hemoglobin (a measure of blood glucose levels over a month), and a low result is pretty weird - likely indicates not an issue with glucose metabolism, but an issue with the stability of RBCs. Since it's happening alongside slightly raised albumin and billirubin, it paints a picture that there's a higher than normal level of hemolysis (destruction of red blood cells). but it's not happening at a rate that's overly concerning. Like I said, methyl-b12 might normalize these results, I doubt that they are central to your PSSD (rather they are probably secondary). The hemolysis could be osmotic, so secondary to pH, electrolyte, and fluid imbalances that come with PFS/PSSD.
Otherwise, I'm not sure which direction you should head in either. I don't see any harm in experimenting with a herb cycle and seeing how you react from there.
If you've been having problems with fat loss and muscle gain, I don't think experimenting with short fasts would be a bad idea either, but stick with an approach and try it out fully before jumping around and trying a bunch of stuff.