Suggest Remedy For Itchy Rashes

I'm 28 years old who stands 5 feet and weighs 100 pounds. I developed pin-sized rash all over my body but more so on my upper extremities. It was really red the first time I noticed it. Now it's less red but it's still there. I can feel thet itch and I can see the red too. My doctor told me that it could be viral exanthem so she had CBC done. It showed that my WBC decreased. She said it's viral infection because of stabs and atypical lymphocytes on the result. She It might go away in 7 days. I'm on my 5th day with this but nothing seems to be improving. The rashes are still visible and seems to increase and it's really itchy. How long will this last? What sort of food should I eat to prevent itching and what should I do if this doesn't resolve in 2 days? I'm freaking out and worried because this may mean something else.