L-Carnitine. D-Ribose is worth a shot too.
burning pain particularly after exercise
I'd guess this is excess lactic acid buildup. I'd try carnosine.
https://www.prohealth.com/shop/product.cfm/product__code/N0530
But honestly, if you're burning, you're probably out of oxygen and need to slow down or stop.
Magnesium malate might also be an option and could help regulate blood sugar as well.
https://www.prohealth.com/shop/product.cfm/product__code/N0668
- high reactivity to stress -
Ashwagandha. Maybe licorice if you don't have high blood pressure or high cortisol. Licorice is GREAT for OI too.
probably hyperventilation, poor breathing, hypoglycemia,
I think the mechanical breathing contraptions are probably the best solution for breath retraining. Alternatively you can look into pranayama practices.
For hypoglycemia, I think you need to try to determine why...is it cortisol dysregulation? Is it insulin resistance? Leptin?
But in general, R-lipoic acid
https://www.prohealth.com/shop/product.cfm/product__code/N1228
and chromium GTF
https://www.prohealth.com/shop/product.cfm/product__code/N0527
are typically pretty safe to start.
some problem with orthostatic intolerance,
Licorice (as mentioned above with caveats), plain sea salt may also help.
head and neck pain, constricted tight feeling muscles in my upper body,
I agree that curcumin is worth a shot. It never worked for me, but it works for many. I think the key is form and dose given the low bioavailability.
This is the best one I've found in terms of taste (none) and the dose is probably around 4g (work up).
https://www.prohealth.com/shop/product.cfm/product__code/PH437
DLPA is also good for pain and it may also help boost endorphins.
https://www.prohealth.com/shop/product.cfm/product__code/N0670
A lot of cognitive issues stem from excessive ammonia. Many people like yucca for ammonia. I don't see yucca on ProHealth though.
Fish oil...but the brand I like isn't on ProHealth and I suspect most other brands are rancid which defeats the purpose. So I'd try astaxanthin. I take 12 mg once or twice a day.
https://www.prohealth.com/shop/product.cfm/product__code/N0597
I'll probably think of twelve more things as soon as I post this...