Glaxony is correct about the hatchlings, but I have discovered another truth and that is many times the parent worm doesn't die!!! I had to learn this the hard way. They are in your system pretending that it left. Later, you discover that the problem still exists.
The problem with taking meds is that the worms become stronger and harder to treat. Unfortunately, this is setting you up for a resistance problem and you may find later that you have more than threadworms causing your problems. You mentioned that Paragone gives you pain -- can you tell if it is the parasites are giving you pain or the herb formula?
You may want to look into an oxygen-based product like Colosan or Oxypowder with a dewormer. Additionally try grapeseed extract and garlic as a remedy, along with another dewormer.