As others have suggested I think you should get your ferritin and B12 tested as low levels of, especially, B12 can cause neurological problems, ie dizziness and a feeling of being spaced out, which often gets worse when under stress. Doctors aren't generally aware that ferritin needs to be around 70-90 and B12 at the top of the range or even higher. If your levels of these are good then you should get a saliva test for cortisol, DHEA etc.
At this stage I wouldn't increase your dose of NDT because if your adrenals need support adding NDT will put them under more pressure.
My experience is that if the adrenals are in a bit of trouble nothing works particularly well other than physiologic doses of the adrenal hormones. Possibly though you could try some adrenals glandulars.
I have looked at Dr Lam's site and he offers very in depth advice, but what he misses, in my view, is that increasing numbers of people in our society are experiencing adrenal insufficiency and if this is the case then any amount of supplements won't actually solve the problem.
I would suggest that you try removing gluten from your diet for a while at least, not because it is the fad at the moment, but because it can affect absorption of nutrients and low thyroid reduces stomach acids thus affecting availabilty of nutrients. Also make sure that you are getting sufficient protein, as this feeds the adrenals. Our diet is so dependant on wheat based products that it is very common for people not to eat enough protein and far too much gluten containing products, ie cereal for breakfast or toast, a sandwich for lunch and pasta or pizza for supper - lots of wheat based stuff and little good protein. Also make sure you are getting good quality fats too as these help the nervous system, olive oil, coconut oil, butter.
Good luck with it all, there is light at the end of the tunnel. Unfortunately it isn't held by NHS GPs unless you are extremely fortunate.