Thanks for your query.Based on the facts that you have posted it appears that you have what is called as Phimosis
If you have not checked your blood sugar levels,get it checked now to rule out Diabetes
as this is common and first presentation of Diabetes.
Please consult qualified Urologist
for clinical examination and to confirm the diagnosis. Depending on findings he may advise you to take antibiotics and anti fungal medications or to get circumcised.