There is nothing much to worry about. If u r feeling pain in penis u can take some pain killer and also put some antibiotic (like povidine ointment) 2-3 times a day around injuries. U must avoid intercourse for at least 7 days to let it heal. Like any other part of your body, your penis can be damaged due to an injury. Injuries can happen if you have rough sex or placed a ring around your penis to prolong an erection. Other probable reasons includes; Phimosis;;happens in uncircumcised males when the foreskin of the penis is too tight and you can’t pull it away from the head of your penis. It usually happens to children, but can also occur if balanitis or an injury causes scarring in the foreskin. Paraphimosis happens if your foreskin pulls back from the head of the penis, but then can’t return to its original position covering the penis. Paraphimosis is a medical emergency because it can stop you from urinating and may cause death of the tissue in the penis.