I´ve been investigating how to restore HPA axis function now for some time. Right now I will be trying natural antidepressants which in clinical studies show different degrees of HPA restoration/modulation. For example low dose curcumin restored it in rats in one study over time. And of course an inflammed and autoimmune gut does not help the hormonal glands, that needs work too.
Thyroid blood tests are only useful for severe cases. For subclinical hypo you need urine 24 h sadly.