sex weekness

i m 31 years old single and i never did sex in my life but in my childhod i use my hand many time. but then i did`t feel any problem. but after 28 years i feel that my ereaction has been week not like before.i don`t have any problem in night discharge. but whenever i saw any beautiful girl or i saw some sceans at tv even whenever i just think about sex then i feel movment in my penis and a trasparent liquide come out very quickly and if this liquide come much after that i feel 2much pain in my testeis (mostly in left testies) and that pain come in my blazer too i did talk with elopathick speciallist but he said its normal when will you merry then this problem will finish automaticaly. but realy i feel that my erection is not strong like before.
i hope i will get better advise from Dr and a very good remedy. but i don`t know how can i get reply in my personal mail address or here.
greating