Imo you should do a proper parasite cleanse for a month before attempting another chelation round. There are parasite cleanses with wormwood, black walnut green hull extract, clove, and perhaps other herbs. You could also eat raw garlic. Here is a link to a website that mentions many antiparasitic herbs. A multiherb approach is best.

http://www.innvista.com/HEALTH/MICROBES/PARASITE/TREATPAR.HTM