Hi, The way you have been holding back, not good for you, you may have weakend your PC muscle, its in the rectai area that you speak of, your PC muscle, does lots of things, its pumps blood into our p***s, it pumps our sperm out and its the same muscle we use to stop urinateing, so if you cant stop urinateing when you use it, then that should hopfully shoud be your problem your PC muscle, your just need to strengthen it up, just go to pegym and on there look for kegel exercises and with these your PC muscle will get stronger, but just get yourself a box of tissues in the bedroom, this way you dont have to hold back anymore.
Good Luck
What age are you? and have you had a psa test for prostrate problems?