Hello Doctor, I Have Impotence And Then I Have Consulted

Hello doctor, I have impotence and then I have consulted my doctor. After he is examined and investigated me well, he told me that my nerve supply to the genitalia is very poor. So he gave me neurobion to use one tablet per day. So what is the effect of this drugs on the nerve? Is drug prescribed for me is correct? I am 30 years old.