You could have something similar to candida overgrowth but a different type of bacteria, viral, or flora disorder. Examples include h.pylori, sibo, parasites, strept, mono, etc.
I would be very careful about any chelation protocol and get a variety of opinions about the subject if possible. There has been a lot of cutting edge research in the last few years and your doctor could be using outdated methods.
Chelation can have drawbacks, especially if you are at a sensitive state or your body isn’t strong enough to handle it…