Hello,
I cannot confirm without examination but the symptoms that you are having are due to balanitis of the penis.It is an inflammation of the glans penis.It can be due to growth of infecting organisms which aggravate it and thus causing difficulty in retraction and pain while erection.Oral course of antibiotics is needed.In addition,pls don’t use any cosmetics on the penis,instead use some topical antimicrobials like Bacitracin or Lotrimin.Also corticosteroids and topical immunosuppressants can be used but they are available under prescription.
Also retract the foreskin daily and soak in warm water to clean penis and foreskin.In case the symptoms persist then pls consult a urologist/dermatologist for evaluation and antimicrobials and steroids prescription.Pls remember that skin disease may take a bit longer to heal in diabetics.So try controlling your blood sugar levels.
I hope it helps. Take care and pls do keep me posted on how you are doing or if you have any additional doubts. Kind regards.
Monilial balanitis.A condition common in diabetics.A course of antibiotic and candid creme will cure you.Make sure that your diabetes is under control.