Scabies not being cured. Help me out?

I have scabies from January or maybe before January. I have taken medicine from 3 different doctors. First one gave a bottle to apply once a week for two time and some tablets to take and a tube to apply in the morning and evening. Next one did same. The third doctor was quite good. He gave me a tube to apply once a week. A tablet once a week and 3 tablets every day. One after breakfast and two before sleeping. And I did this for two weeks. The time I was taking medicine I was all good. As soon as I stopped it came back. I am really tired of this. What can I do to cure it? It is really frustrating. Is this about my eating habits? I take a good protein diet. And I can't tolerate much heat. Everyone is alright when we all are standing in hear but I get wet in sweat. In winters, I can't wear much clothes. If I do, it starts itching. Can you help me out?