What you describe sounds like numbness and numbness is usually because of a nerve issue. An injury can definitely cause this and does not need to be a fracture. When this happens (damage to nerves or blood vessels from injury), it gets better on its own. If this lasts, see a doctor. If you are particularly worried, see a doctor now. It sounds more like that than a friction issue caused by too much intense masturbation (in which case, one should stop the activity and let the penis normalize again). There are underlying conditions that can cause nerve issues like diabetes but you don't really sound to be in a position for that to be a concern. A physical could rule any of those out though. You still have desire, right? So, testosterone is probably not the reason either. I'd guess since you heard a pop, you suffered an injury that needs to heal and you'll have to be patient. But again, see a doctor. This article goes through potential causes for your symptoms. https://www.medicalnewstoday.com/articles/322694