No end in sight - Scabies

Please anybody help if you think you can. I have been itching now for seven months. It first started as flea bites from my sisters cat. When I moved from there to college, the itching got really bad. Treated myself with a herbal formula for Scabies but didn't work. Was then convinced it was some allergy or Puritus. Finally, I had given it to my friend - i then knew it was Scabies. I have now treated myself six of seven times. Seen a doctor about five times. None has been much help. It is possible I suppose, that they have gone and I am just waiting for the toxins to clear. I don't know though, and the Dr is refusing a to do a test with a skin scrapping.

I am worried about my next semester. I am worried about the worsening condition of my skin. I am worried about giving this to another person. I am worried about all the stress this is causing me.

I have used Derbac and Neem. I only have access to a shower, not a bath. I feel so miserable and alone. Please someone help me. I have had scabies for about five months. Is there no end in sight?