Help?

Brie
For some reason no matter how great the guy is, how big or wide, or how amazing the sex, I feel like I can't orgasm. I feel bad because I feel like I'm making my man feel like he isn't performing as best as he can.... I've had a lot of sex and there is only one time that I think I have really felt anything building up and an actual release. What do I do?! Totally desperate for help guys lol....