Central Pain (reminds of P)

hello my name is xxx and i have had a problem with my penis for a couple of weks now..i love to masturbate to porn but i keep doing it like twice everyday..so to get to the point.my penis gets erect no problem..hence..when i am about to cum only the rest of the wanking feels fine, i feel this sharp pain go right through the center of my cock shaft like someone is cutting me so the pleasure greatly diminshes and my time was wasted due to the pain so i yelp and stop..what is this pain or rupture?should i just stop wanking for a while until i heal or produce more sperm?i feel nothing taking a piss or anything elase just when i am about to cum during wanking..regards xxx

please asap if possible i am a little worried here and probably about nothing..lol