My penis becomes quite sore whenever I get an erection. This has been going on for about a week or two. The pain feels to be internal and primarily towards the last inch or two near the head. Other than when I have an erection, it feels completely normal with absolutely no discomfort. There is no pain when I urinate nor is it sensitive to pressure when flaccid. There are no external signs of anything wrong (like discoloration, spots, lumps, etc.) and I don