Do you mean that you cannot physically orgasm? Or do you not attempt because of the pain? Please explain the problem a little better.

the problem of irection

The proper term to use for trouble getting or keeping an erection is technically called "erectile dysfunction", or ED. If you're experiencing ED, you need to tell you doctor about it. Erectile dysfunction can be a sign of health problems. If you don't see your doctor, these problems will go untreated. Problems include:

clogged blood vessels are clogged
nerve damage from diabetes

Your doctor can offer several new treatments for ED. For many men, the answer is as simple as taking a pill. Getting more exercise, losing weight or stopping smoking may also help.