Firstly, your erection is not hard enough to penetrate a woman’s vagina. IT might be caused by tension of blood cells in your penis – they do not let the blood flow as they should and the blood rushing to the penis gets „blocked“ and „hindered“ on its way, thus making the penis not hard enough. This is also one of the easiest things to actually cure with any pills for erection. Secondly, it might be that you are unable to make the penis hard for a long time. You sheath your sword at the start of the battle and then puff, the penis goes numb in the middle of the night. That is a huge deal breaker for every man and a punch to the face of every partner. And lastly, it might be premature ejaculation, a thing so common, it might be a syndrome on its own.
Is there anyone I should consult?
You might visit your general practitioner or family doctor and consult with him the possible treatment. It is also important to highlight that these happen to almost every man at least once in his life – it doesn’t mean you are impotent, when it happens HOWEVER if it happens a second and a third time, you might consider it to be a problem.