Dosage adjustment of thyroid hormone replacements is still an art since inappropriate dosing can result in symptoms of overtreatment or undertreatment with further complications including cardiovascular problems, loss of bone density, and neurological disturbances
As you say you've " tried oral B12, which made no difference " it may well be that you have an absorption problem and will need injections
doi: 10.1016/j.arcmed.2020.04.019 58 DenekeS
Results Fragment-based drug design and chemistry Utilizing actives identified in a quantitative high-throughput screen against Schistosoma mansoni TGR 20,35 , 92 commercially available low molecular weight (MW) compounds/fragments were tested by X-ray crystallography 33,34,36
Meijerman, I., Beijnen, J
Resources, XW and RW