Low sodium can also cause alot of the problems you mentioned.
A good salt I found that seems to work for me is from Dr Larry Wilson's protocol( I am doing) Hawaiian Bamboo Jade Sea Salt ...a little costly but for me it is worth it, I have been able to get off of fludrocortisone (so far) and my head is not swimming and no dizziness..I put it on all of my food I consume... Have you had any blood work done, How is your sodium levels???
Marie