Erectile dysfunction is defined as the inability to develop and maintain an erection during sex. Therefore, even if you are able to get an erection, if you have real trouble maintaining it, then you have erectile dysfunction (albeit probably very mild erectile dysfunction). Viagra and Cialis are drugs that act to increase blood flow and blood trapping in the blood vessels in the penis. Therefore, they only help if you have some blood vessel disease in that area. Since this is the most common cause of erectile dysfunction, it means that these drugs are most likely to help you. You may even be able to try a half or quarter of the recommended doses to see if it helps.
I suggest that you schedule an appointment with your primary care physician
or internal medicine doctor
. He or she can take a more detailed history of your erectile dysfunction and perform a physical exam. Erectile dysfunction from blood vessel disease is fairly easy to treat. If your doctor diagnosis you with ED, then it would be a good idea for you to make sure that your blood pressure and cholesterol are in check to avoid or slow down any progression of the disease. Good luck.