I have been having unprotected sex with my girlfriend for the past 2 months and everything was fine the first month bt recently i have a part of my skin on my penis that is raw....and when we have sex it tends to burn. this is the first time this has happened and im wondering could it be an std?? another issue that has recently happened is itchying of the testicles.....now it could be possible that it is jock itch but im not sure. what could be the possibilites of this problem??