Honestly? I'd dump him and not look back. Seriously. How selfish can you possibly be? If you're so squeamish about the way the human body naturally works during sex, then you shouldn't have sex. Or you should find some other prudish, selfish jerk who will also act like a child when confronted with body fluids.
Sorry, but this kind of thing really pisses me off. It's not going to get any better, either, if he refuses to open up about it. You are going to grow more and more resentful and feel more and more hurt as time goes on, and it's going to trickle out into every aspect of your relationship. He's already managed to make you feel insecure about how your own body naturally functions during sexual arousal. Why would you stay with someone who makes you feel bad about yourself?
I might sound harsh, but I hate it when people act like this about sex, and they just drag their partners down into the dirt with their selfishness, and their immaturity. And stop going down on him, for fuck's sake. You may enjoy it, but he doesn't deserve getting head. At all. He won't even use his hands to pleasure you? Why are you with him?
Maybe he's gay and in denial. Seriously--any man THAT squicked out by a vagina is probably sitting in the closet trying to convince himself that he's not gay.
Maybe you should ask him how it feels to be a bad lover? How it feels to have an unsatisfied girlfriend? Does he feel good about himself knowing that he sucks (only figuratively) in bed?
Don't be quiet about this. Don't be apologetic. Don't feel insecure about your own body because of him. Don't back down. If he won't stop acting like a baby or a closeted gay dude, then leave. There are plenty of men out there, most men, who would love to eat a nice, wet pussy. They'll worship it, and the wetter you are, the more they'll enjoy it. Stop wasting your time on someone who is too much of a pussy to eat one.