good evening DR,i am a young man of 39 years old,during sexual contact,ireally irrect very strongly,and i take 45to 50 minuts,but when it is time to releace sperm,i will get the feeling that am releasing sperm,but at the end no sperm will be seen,i use condum to verified,but no sperm will come out,almost 6months now,this worried me a alot