Orgasms

Do any of you ladies have a hard time orgasming with your partner? I have NEVER been able to cum with any of partners. My partner and Ihave amazing sex and I enjoy it so I guess I feel bad since I'm not able to. The weird thing is that when I masturbate (panties on) I have the best orgasm. We have tried having sex with my panties on and it just doesn't work out. Am I broken????