How can i find the doctor who can enlarge my penis and stay strong?

You should see a Urologist. But there is no recognized surgery which can enlarge the penis. For a stronger erection he/she might give you medicine e.g. Viagra and also try to find why a young man like you need to have help to 'stay strong'

You have all the ability to use what you have. If you lasted all these years, remember, it's not the size of the gun but the ability of the gunner to shoot it. Staying strong includes a healthy diet and exercise Don't try any methods to enlarge, it could be dangerous.