It is not typical to have that much difficulty to fight parasite (-but you would get a better feed back from the parasite forum here at Curezone) however it IS typical to have that much difficulty to fight candida.
First you must make sure you get rid of the parasites, Second, you must heal the leaky gut (if you feel pain down there it is not healed). Marshmallow helps with inflammation/bowel pain. It soothe the inflammation which will help your body fight out the leak. Not eating anything you are intolerant to and following the candida diet strictly should also help you get rid of that pain.