Mercury and polydipsia/ renal failure - plea for help

Posting out of desperation and fatigue.. Am at my wits' end. I have been experiencing polydipsia (extreme thirst) for the past 3 or so years (since I was around 18). In short, it means I have to drink about 12 or so liters of water daily in order to maintain my health/ hydration levels. This may not sound like a particularly onerous occurrence, but it has surely caused me severe amounts of distress/ anxiety, up to the point of contemplating suicide. I won't bore you with the consequential logistics.
Basically I have been from doctor to doctor, and having done all of the preliminary testing (eliminating the usual suspects, namely diabetes and/or an endocrinological issue) they simply dismiss me and fail to acknowledge my symptom to be of any importance at all. In fact, some have even gone so far as to suggest that I am delusional (because nothing can be verified through a blood test, therefore I am delusional?) Before too long, I came to see a holistic practitioner (who was also a certified gp). He told me he had another patient with the same symptoms as mine, which turned out to from mercury toxicity. He ordered a hair analysis, but it wasn't until some months later that I received the results (due to a complicated set of circumstances I had found myself in). When I received the results, it seemed a welcome relief. After much endless searching, it was like seeing the proverbial light. After discussing the results quite briefly with my doctor over the phone, he came to assert that it could not be the mercury, as my levels were not high enough. He too was stumped. By this time, I was already far too convinced that what I was experiencing was due to mercury toxicity (the fatigue, nocturnalism, brain fog, lack of focus, irritability, and other mental health/ behavioural issues I had been experiencing since the age of 15, as well as extremely high levels of selenium, candida, being an avid seafood lover, and a myriad of aches and pains), and of course I was swept away by the mysticism and mythology of it all. I conducted alot of research into mercury toxicity, trying to establish a connection between the polydipsia and mercury. What I discovered was an abundance of medical papers and clinical studies evidencing that mercury had a clear and demonstrable effect on the kidneys and their filtration efficacy. I immersed myself in the literature, and looked further into different chelation methods. I saw my doctor again in order to perform another blood test (which came back as too low to be significant) and yet again dismissed the possibility of mercury affecting me, before suggesting a dmps challenge, only to placate me.
Probably too unnecessarily lengthy for a background story, so I apologize.., basically, the issue at hand is that I couldn't/ can't afford to see my doctor again in order to obtain my results. I got impatient, and started taking the NAC, ALA and Chlorella that I had been stockpiling for my prospective therapy. The NAC and Chlorella ran out pretty quickly, and I didn't feel any differently, but I continued with the ALA. I was pretty lax/ inconsistent with the dosing, and stopped taking it altogether for a day. Since then, I have noticed my symptoms worsening, (water retention, bloating, back pain, severe cramping and thirst) I'm vacillating between complete apathy and catastrophization.. I don't know what to do (whether I should continue with the ALA?) or who to turn to!? I'm in Sydney, and alas there seems to be no doctor in sight that knows what they are doing!
I'm so lost, I don't even know what I'm asking here.. any input/ suggestions are appreciated though.