I too thought I had scabies for 10 months and took all the med you have mentioned -- then I got a microscope and found the springtail -- I have been doing megan's protocol from stopskinmites.com
and my skin has greatly improved. the black specs that come out f your skin are fungus. getting rid of the springtail is key to getting rid of this terrible scourge. I am having problems clearing my environment--- just a thought -- you may want to check out the site