It is healthier for you to have both the release of an orgasm and to enjoy a sense of intimacy. This is true physically and relationally, and he should be providing that for you. It sounds like you've tried to communicate clearly about your feelings, but you might explore with him what his feelings are in response to your frustration. Often men feel threatened by any suggestion of their mate's dissatisfaction. There are many possibilities for his lower drive and for most males they are scary to look at.
Denial is usually the first line of defense.
It just doesn't feel right to a man to admit he may not be sexually adequate to meet his wife's needs. If he were willing to talk openly with you that would be a place to start. You can talk about your sexual histories. There are many life events that can affect a man's sexual drive through guilt or anxiety. He may even have low testosterone level, which a medical evaluation would reveal.