How much vitamin C do you take per day and per dose?
If you've only been taking Vit C and Li, there is much more out there for you to try! If indeed Hg is involved, there are countless people who went before you and got much improved.
Check out this engineer/physicist who had been almost bed ridden with chronic fatigue, mood and other issues. After Amalgam removal and a year or so of detox he was back at work full time. He got additional gains over the following several years. https://www.youtube.com/watch?v=wE_bjZ4kdJI