Thanks for your query.Based on the facts that you have posted it appears that you are facing problem of Erectile Dysfunction
You have Diabetes and Hypertension
which are known causes of Erectile Dysfunction .
Please get your blood sugar levels tested frequently to check the status of your diabetes.
Following measure will help you to boost up your confidence and getting good erection.and delay ejaculation.
1) Practice regular exercise for 45 minutes followed by meditation
for 1/2 an hour in the morning.
2) Take high protein diet rich in vegetables and fruits and Vitamin A
3)Take anti oxidants like Almonds 5-6 everyday..
4) Avoid alcohol and smoking.
As you are already taking (hopefully) Sildenafil
to get erection you have to continue taking it ..