Thanks for your query.Based on the facts that you have posted you have type one diabetes and has itching of the penis -with red spots on glans penis..You have acquired fungal infection
what is called as Mucocutaneous Candidiasis
which is very common in uncontrolled diabetes
.Please get your blood sugar levels done to check whether your diabetes is under control or not.and take some anti fungal medication
like Flucanozole orally as a single dose along with tropical anti fungal gel for local application/Get the prescription of these drugs from your family Physician.