Your scenario sounds like dumber and dumber -- I don't mean to be rude or disrespectful but the run around is unbelievable. Many doctors have forgotten how to be doctors -- the entire body has been divided into parts with subspecialities practices. The right hand no longer knows what the left hand is doing. Once upon a time... doctors viewed the entire body and they were able to do proper doctoring. You should make a movie. I bet it will become a big hit because everyone can identify with it.
I can tell you for a fact that the ER will not be able to help you and you'd be wasting your time.
You may have better luck if you take a different tactic. Call the CDC or "poison control". Ask them who or what institution would treat someone for lead or mercury poisoning. What is the usual protocol and are there specialist for this. An Immunologist might be another possibility... actually, that might be your best bet.