May u have Peyronies. Deformity of the penis can be congenital ( born with it) or acquired usually following injury to the penis -many men don't remember any injury to the penis- this is called peyronie's disease and occurs in up to 9-10% of adult men. U should be evaluated by a urologist with expertise in this problem or sexual medicine in general.
?Interferes with Sex. 1) has this been present since birth? Or is it a result of a sub-optimal circumcision and both should respond nicely to reconstructive surgery. 2) ? Developed later in life plus has a hard "plaque" under the skin on the upper side of your penis would be peyronie's disease. May improve with therapy. My advice is to consult with a reconstructive urologist unless you still have no problems with sex.