This might be a retarded ejaculation problem. I have been fighting this and I think I may have found the answer.
I am able to keep an erection for hours if I want to. But I was not getting an orgasm or ejaculation. There are many possible causes according to the literature. So I will not go into all of that here. But let me tell you about a discovery I just made.
I have been able to get great urges to cum, but I could not get myself to the point of no return. It felt good but it did not give me the release I needed. I could go for hours feeling good, but not enough.
So I just tried something different. AND IT WORKED! When I masturbate I use a fleshlight. Great device. But still had problems. Occasionally orgasmed, but most times I could go for hours and not cum. So I used a combination of a Hitachi massager on the base of my penis and stroked with the fleshlight. I got myself near the PNR (point of no return) and held back. Then I continued again (just like edging).
THEN I STOPPED FOR ABOUT 15 minutes. WITHOUT using my Hitachi I stroked myself and got near to PNR and stopped. I stopped again for a longer time interval and found i could restart, without any assistance from my massager and go to the PNR within a couple of minutes. I then went all the way and had a mind blowing orgasm.
NOW WHAT DOES THIS MEAN TO ME? I think that if you can figure out a way to get yourself up near the PNR a couple of times, you have conditioned yourself to do some serious fucking with no external help (other than the worman) you have overcome the problem. So for me the key is to create the sexual tension and resulting emission to set the stage for orgasms when you are ready.
Of course you may be saying.. what do I have to do to get near the PNR? Well that is an individual thing. Many options. But once you get there you can then start screwing and cum whenever you are ready. You are in control.
BTW: one of the most common problems with not being able to cum is if you are so concerned about pleasing your partner that it affects you. It seems to be all mental issues, and fortunately not a physical problem. So go work on this.