Thanks for your query.Based on the facts that you have posted it appears that you have problem of itching of waist due to dermatitis
.and erectile dysfunction
As regards itching around the waist it could be due to dermatitis due to tight clothings You can try using steroid cream after consulting Dermatologist
.As regards size of the penis ,the size of the penis in flaccid state has no significance it is hardness that is important from the point of view of enjoyable sexual life .
Your problem of erectile dysfunction could be due to smoking which is one of the commonest causes of erectile dysfunction.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.