low serotonin, candida, and mercury

All my life (or really, since my first filling as a child), I have been plagued by low serotonin levels (anxiety, OCD, depression, etc.) and what I believe to be candida (fungal skin infections, horrible Sugar cravings, digestive disturbances, etc.) I have taken anti-depressant drugs for the past seven years at least, but now they seem to have stopped working. I have at least 4 metal Amalgams in my mouth and am wondering how likely it is that these could be related to my physical/psychological issues. Also, is mercury really only a problem if high levels of it show up on a blood test? If I get tested and my results come back within a normal range, does this mean that mercury is probably not a major concern for me? I'm thinking about getting my fillings removed, but I know that it's going to cost a FORTUNE and I have NO dental insurance. So I just want to be absolutely positive that I have mercury toxicity before I attempt it. I guess my basic question is this: in my case, how can I be absolutely positive that mercury is causing my other health concerns? Any information would be GREATLY appreciated. Thanks! Tweet