My suggestion is to change your scale. Before she had this intense orgasm, you would have said that your orgasms were a 9-10. But once you experienced this special orgasm, suddenly what seemed to be perfectly delightful orgasms dropped down to a 5-7. Psychologically that’s damaging because it’s making you dissatisfied with perfectly good orgasms. So why not rate that special one a 12 or even a 15, so that your regular orgasms can resume being 9s and 10s. As to repeating that 12, my guess is that the harder you try, the more unlikely that it will happen. So just put it out of your mind, and if it happens again, great, and if not, just enjoy your sex life as it is.