Dude, where's my orgasm?

Ok- I'm sure you guys are all tired of this question but believe me, it doesn't get old when you have to live it day to day!
I'm twenty and I've been with my boyfriend for a year now, he's my first serious relationship and sex- i had sex a few times before with a random guy but it was more trying it out than anything else, nothing compared to the intimacy and how comfortable i am with the guy i have now. The problem is: now that we've experienced so much together, that we live together and share pretty much everything, i'm starting to wonder what the hell could be wrong with me/him/us that i haven't had an orgasm during sex yet???
Believe me- we're in love and VERY comfortable with each other and each other's bodies and willing to try out new things. We usually have sex every day or every other day going through about five positions every time. There are some that feel really good: like when he puts my legs up on his shoulders it sends shivers up my stomach and down my back!
But it's very frustrating as it all stops there. Every time. Is there nothing i can do???
I have a vibrator, he has a cock ring. I have fingers and am not afraid to use them. It just really bothers me that I can never ever come without them. And when I do- I feel and know perfectly well that I'm the one making myself come, not him, and that whether or not we are having sex makes absolutely no difference.
I hear and read girls (even on this site!) talking about how they come every time in this or that position but why can't I?? Is there something wrong with me or my boyfriend? It's been a year and it's starting to really bother me. Help!