dmpsbackfire.com is full of reports of terrible worsening from IV chelation
There's also people who say cilantro and chlorella are safe whilst I and many others had horrible worsening from it. I personally am doing much better with 6 months of Andy's protocol. Just because people say something is OK doesn't mean it is. That's the good thing about the Cutler protocol.. it's not just some random guy spewing out information. It's information backed by Science and logic aimed at maintaining a steady level of chelator for long periods of time and minimizing redistribution.
If your not getting better I would be more concerned about the diagnostic phase rather than the treatment.
If you do have mercury toxicity which a DDI hair test would probably tell you, Andy's protocol is the way to go.
If something else is going on you may consider obtaining a diagnosis.