Omg I have all the same problems, exactly! I had my fillings out on April 15th and instantly ft better. Get them all out ASAP. There's some online protocols for taking DMSA but you should try to find a naturopath to help you. I bought some but when I went to my GP to have my mercury levels checked my blood work came back high cell count, might be blood cancer, I don't know if it's from mercury poisoning or not. So I have to wait for the chelation but the toxic headache was gone the next day. I still have really bad nerve damage all over my body and my spinal cord is burning on the left side of my neck but not like before. I take 2 ml of fermented cod liver oil every day to help repair and I think it works.
Good luck on your journey.
Michelle