When a man is masturbating, he has one goal in mind: orgasm. When he’s having sex with a partner, that goal is still there, but there’s also another goal: pleasing her. The very fact that there is another person involved with her own needs can be distracting. Some men find it more distracting than others. Obviously there are also a lot of advantages of there being two people rather than one, such as the touching of two naked bodies, the aural pleasures, and the sharing of love, so overall, most people find sex between two people far superior than masturbation.

If there are relationship issues, then that could change, of course. I have some suggestions for you. First of all, instead of always giving her an orgasm after you have yours, why don’t you mix it up a bit? The variety will serve to keep away sexual boredom. But you may find that if you know that your girlfriend has had her orgasm and is sexually satisfied, then you’ll be able to better focus on your pleasure, as you would in masturbation. If you are better able to concentrate, hopefully you’ll have a better sexual experience. Finally, you say that you’ve used a ton of different sex acts, but I wonder whether you’ve used them to try and have orgasms during intercourse. Some couples find that a particular position is helpful, especially the ones where the man’s hands are free to stimulate his partner’s clitoris during intercourse. This requires that he be able to last sufficiently long and that his partner has her orgasm. However, since you seem to have some problems having your orgasm, it doesn’t seem that you are a premature ejaculator. In any case, let me know how this all turns out.