Hi Briand, This is what you get for holding back, to much justvtry letting it go from now on, you could end up with retrograde ejeculation, this is were you ejeculate into your bladder, not the kind of safe sex you need.
If you want to keep doing this google pegym and look up edging, this is an exercise for extending extending your time with your g/f, but not as bad as what your are doing now.
Good Luck
Well, how old are you? Just curious, because knowledge of these things usually come with age.
Anyways, without sounding inappropriate, but this sounds like something they call "blue balls", literally. When aroused, blood is rushing and accumulating in the area, and when not released, can cause a pain, also can cause nausea.