Why can’t I orgasm from penetration?

Please help! Me and my boyfriend have magnificent sex all the time, but he can never make me orgasm from penetration. Lately he has been beating himself up about it, but I continue to remind him he doesn’t have to worry. But I feel this is becoming a huge issue in our relationship because Everytime it’s time for us to have sex, he makes it his personal goal to make me orgasm, which is now mentally draining me and becoming almost like sex is a chore because he feels like he has to make me orgasm during sex and I don’t think I can. I never have at least.