Hiya
I honestly dont knw the name for it, but, the popping sound happened to my bf during sex with me --- after that it slowly started to hurt when he climaxed to the point of him dreading it --- it turned out when he popped it, that caused fluid to start to build up at the base of it -- he had the fluid removed and no probs since --- While your after effects of the popping are different, I really really recommend getting it looked at
One last thing, he couldnt detect the fluid himself, there wasnt any lump anything -- it wasnt obvious from the outside
Try this, just leave your masturbating to your g/f to for you, or better still just leave it alone for a couple of months, the body is a great healer if you let it, get on to a PC/keduls program this will strengthen your muscles and get you shooting better, and it works.
But at lease you can still have sex and that helps.
Good luck
Best bet is just to go see an urgologist. They can tell you more than we can. Trama can often lower testostarone levels which will make you lose hardness. Are you tired and drained alot? Then may you have low test. Should be around 900 for your age. Anything less IS NOT NORMAL RANGE.
Do it now. Go see a doctor. Nothing to be embarrased about. It is worth it.