Suggest Treatment For Rash And Itching On Wrists And Back

i have had a rash for about almost 7 weeks now, at first it wasnt visible and it just itched it started around my belly button then my side where my bra lays and my wrists. The area on my side under my bra got really red and big bumps, that went away and the rash spread to the rest of my body, non visible untill itched. Its unbearable itching. NOW the rash is visible on wrists and belly, a little on my back. it sometimes is so bad i get nauseous. Ive been to a free clinic for help, first he thought it was an allergic reaction to a soap, and that it wouldnt go away without treatment. Ive tried Hydracortizone and nystatin creams for my body with no help. Then the dr gave me Vistaril which doesnt take away itch but it dehydrates me and makes my muscles sore . . I cant sleep, i also felt like i had a fever