Hi, I am new here but I think the die-off of the parasites will produce toxins which are getting into your bloodstream. This will probably be what is causing the feelings of being unwell. Upping your intake of water is always a good idea when trying to detoxify.
I am a kinesiologist in the UK and use herbal capsules to help my patients get rid of parasites. I upset another one this morning by finding that she has nematodes but she will feel a lot better when she has got rid of them!