Hi Shawn. I'm probably different from people here, I don't want to attribute many of your symptoms directly to metal toxicity. I have known for some time that there can be amalgam-like illnesses without any mercury involved. These cases tend to fall into the chronic fatigue syndrome cases (CFS). People with CFS have a big problem with parasites. Candida, lyme, viruses, mycoplasma bacterias etc. You may want to know that candida is the first that invades your body when your immune system is compromised. Candida in itself can cause any of the mental problems you mentioned, in addition to sensitivity to electromagnetic fields. Candida can also cause mineral derangement, and CFS sufferers in addition to mercury toxic people have usually high copper levels in hair. Mercury is a potent immune system supressor, but your exposure must be continuous to it, so that it will make a difference. Otherwise your immune system is back in business once the exposure stops (provided you haven't gotten other parasites meanwhile that weakens your immune system). With mercury in amalgam fillings you cant stop the continuous exposure, until you remove them all, so there you go.
But back to your problem: as you suggest yourself, you likely have a genetic deficiency. Sufferers of CFS may have a problem with glutathione transferase genes. You can also have hemochromatosis, a genetic deficiency that causes excess iron to store into your body, and this causes oxidative stress and leads to various organ damage in liver, joints and heart, and is relatively common (perhaps less than 0.5% of the US population have it in its active form).
There are of course many other genetic deficiencies than these, so you should consult an expert that can determine what your problem is. This can be tricky, but once you know exactly where your problem is, you can perhaps target it better.
What is good is that you can make up for some of your body's deficiency by supplements. Alpha lipoic acid, whey protein, various vitamins can boost your immunity enough to keep the parasites and candida away. But it is a very tedious and stressful thing to kill the pathogens that have already invaded your body. Candida are the easiest, but some of the nastier bugs like mycoplasma are hard. So hard that nobody knows yet how to deal with them efficiently. Antibiotics can be used, but they also destroy the good bacterias, and candida can again take over.
Hope this helps.