dear sir, i am very sorry for your condition but it can be treated so dont worry. the problem that may cause penis pain during intercouse/doing sex vary from infection,herpes,dermatitis, prostatitis,and phymosis read from what your condition, you may check first does your penis foreskin is too thight to be retracted during errection because if that is described your condition, that called phimosis that may cause pain during and after intercouse and the solution is doing circumcision. you may also check did u suffer from herpeszoster, because penis nerve became sensitive if you didnt have herpes zoster and that very infectious other infectious such as urinary tract and prostatitis can made sex painfull yeast infection can also made itching and burning sensastion in the tip of your penis. in my opinion the phimosis can be the cause from your problem and circumcision is the solution. i hope my answer will help you to solve your problem.