I can't have an orgasm. I can only have one if I do it myself. I don't understand because my boyfriend is big and it feels right. But for some reason I can't have one. I never have, except with myself. Any suggestions on different position we can try because I have tried everything I can think of. Or maybe there's something else we can do to make it happen. I need help. Please.

Are you attracted to him? Does he consider what you like and want? If he does I am glad. Big is nice but its not the most important thing. If everything else seems OK try something different or somewhere different.