Hi,
Welcome to the ehealthforum. I am glad to help you out.
Not having any erection after ejaculation is a normal phenomenon.The time taken to loose erection after ejaculation depends on individual to individual.Some males have erection even for 30 minutes after ejaculation. Also, typically after ejaculation or orgasm, sexual arousal wanes. As that arousal goes down, so does an erection.
During an erection, the blood vessels of the penis constrict to allow the erection to occur. If that constriction continues for too long, the cells can actually be damaged. This condition is called priapism.So normally erection goes after ejaculation.
It is very difficult to precisely confirm a diagnosis without examination and investigations, and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.