I am always concerned when I hear of chelation being performed when mercury still exists in the body; Even in teeth. I generally don't believe this is a good idea because teeth are living tissue and can pass mercury through it. My dentist recommended against using even chlorella until all amalgams were removed.

DMSA is pretty powerful so I might recommend getting a second opinion as to whether it is a good idea or not to be using DMSA with that mercury still in. Perhaps this is the root of your problem and may explain why it's taking so long to feel better.

Please don't be discouraged. There is a cause for everything and getting better is simply taking the time and putting in the effort to finding that cause. The amazing thing is this: When you do find the actual cause and fix it, all the problems normally just go away. This is the good part and it seems that you're most of the way there. You just need to find out if the remaining mercury in that tooth is at the root of this issue. You've come this far, don't quit now.