The itching can be stopped by applying Vaseline or Noxema. You can also use generic vanilla frosting that comes in a can at the grocery store.
Buy cheap sandwich bags. Place one over your hand, scoop up the frosting and apply to your bottom. The itch will stop.
Now add something known to kill pinworms: black pepper, choriander ground, cloves.
Be creative. Use stuff that might kill the worms. Add salt, crushed aspirin, outdated meds, sleeping pills. What ever you have.
Remember little of this will be absorbed by your skin as it is in the frosting.
Wear disposable briefs if you can.
Use baby wipes to clean your bottom.
Wash your hands often. Keep nails short.
Go to a Pentecostal church and ask the elders to place their hands on your head and pray for you in the Name of Jesus Christ. Do not confide in anyone. Just say it is a problem with intestines.