Was diagnosed strep throat and now i have a blistery rash on my cheek and it is painful burns and itches what can i do to help it go away?

Hard to say: It is hard to say without visualizing this rash. Several possibilities come to mind which are common. You may have an shingles rash, which is a is a blistery, painful itchy rash which covers in the distribution of your nerve roots (dermatomes, we say) Could possibly be impetigo, a bacterial skin infection. I would start with topical neosporin for this. For treatment will need Prime Exam