If you want to be more successful with your partner, stop all masturbation and use of pornography. When you masturbate, you are using up your sexual energy that could be put to better use for the benefit for you both.
Are you circumcised? This is an issues that occurs sometimes with circumcised men, because they have had most of their penile nerves cut off. If that is the case, then my only suggestion would be non-surgical foreskin restoration, which helps to some extent to restore sensation. It takes several years to restore a foreskin in that way so there is no immediate relief, but once done, it lasts the rest of your life.