I second shi in exploring any potential medical issues.
Forgive the instrusion, but have you or do you do kegel exercises? Aside from the medical benefits, exercising your vaginal muscles may help you achieve vaginal orgasm. Don’t freight them with that expectation or expect it to happen right away. Go into it with the idea that strengthening your vaginal muscles will increase your sexual pleasure (and probably your husband’s too). The reason it may help is that contractions of the vaginal muscles are involved in the female orgasm. So, in effect you are “practicing” having that experience without clitoral stimulation.
I would say that you need to take this off the table as a goal of your lovemaking. it is too stressful for both partners. It means that if you don’t, you have failed (and he will feel he has failed to pleasure you). For now, go into your lovemaking with the idea of pleasing each other and spending intimate time together. Stop counting the ways and means of orgasm.
You did not mention the role and length of foreplay during your lovemaking. Women need much longer than men before they can climax, especially vaginally. Have your partner spend some extra time on getting you ready. Ask him to do the things that make you particularly hot (that will excite him too). Using clitoral or oral stimulation have him bring you almost to the peak of orgasm once or even several times, and then begin intercourse.
Good luck. As problems go, this one is at least fun to work on.