i AM TAKEN IVERMECTIN FOR SCABIES,, MY WEIGHT IS 215LBS,, AND I AM TAKEN 6- 3MG TABLETS,, IS THAT ENOUGH TO KILL THE SCABIES FOR MY WEIGHT.. I AM 67 YEARS OLD,, AND SHOULD I DO SOMETHING ELSE TO KILL THESE LITTLE MITES. IT SAYS I HAVE TO PAY 15 A MONTH FOR THIS ANSWER?? IS THAT CORRECT??