Have you tried taking some adrenal cortex only on a daily basis for a couple of weeks and seeing how you feel. If this supports your adrenals sufficiently you might then be ok to reintroduce half a capsule of the thyroid product. Do you know what the dose is that you are getting from half a capsule?
I have been taking dessicated thyroid medication since 2002 and I have definitely learned that one has to have strong adrenals to get real benefits and no side effects. It's been a great help for me but I have to take a steroid as well because of adrenal insufficiency. If anybody has a problem of weak adrenals then taking any thyroid meds will soon bring this out into the open and one will feel a whole lot worse.
When I tried building up thyroxine instead of dessicated it was a disaster, it made me completely toxic and that was just 50 mcg whereas I tolerate 2 grains of dessicated thyroid (1 grain on waking and 1 grain lunchtime). I would never repeat that trial of thyroxine again but I do fine on just 25 mcg which I take along with the dessicated thyroid.
If you are hypothyroid and you find the right medication for you it can make a massive difference to how you feel, well at least that is my experience.