IMO its kind of a lost cause to try to draw linear lines through issues like this (ie. Adrenal fatigue -> low HCL -> Candida -> leaky gut). I don't think the body works that way, and they will all need to be healed anyway.
But they are almost always linked one way or another. I have been in a similar boat, and recently have switched my diet to a kind of a lazy vegan diet which has helped a lot, as have L-glutamine and aloe vera.