Feeling a little bad is typical if a chelator is working. I usually feel worst on the second day of chelating and tired on days after the second. Symptoms I have include difficulty paying attention, emotional problems (including difficulty feeling satisfied, feelings of regret and irritability) and others. They are temporary and as I've continued chelating have affected me less and less.
I've never used the supplement you are using, so I could be wrong, but I suggest you not follow the schedule they put on the box (supplement companies, like a lot of doctors, don't always seem to really understand chelating). Take any chelator every 3-4 hours, including waking yourself up in the middle of the night to take it at least once. Do that for 3 to 5 days with a 3 to 5 day break. This is a program for keeping the chelating effect going and preventing redistribution. I usually suggest people continue to take chlorella for a day after finishing with cilantro, but that won't be possible with the supplement you're using (that's one of the problems with using a blended supplement).