Your boyfriend sounds like a chump. Not necessarily because of the situation, more how he handled it (like a grade-C chump). The fact that women regularly consent to giving men oral sex all over this great nation of ours is one of the only things that keeps America from falling to communism, and it should be greeted with joyous gratitude. Why, he should get down on his KNEES and...look you in the face? I digress.
Yeah, when we kiss you after you've given us head, it can taste like dick. So the hell what? It tastes like that because you just repeatedly stuffed his penis into your mouth. Anyone you give oral sex who responds by rejecting a romantic advance and equating you with disease DOES NOT DESERVE YOUR ORAL SEX.
Maybe it's an "I don't want to seem gay" thing? Although that doesn't really hold water when you're literally in the act of heterosexual sex at the time the argument arises. Plus it's your own penis, which is like calling masturbating gay. And if masturbating counted as being gay, Prop 8 would never even have made it on the ballot.
This guy sounds like he's got serious common decency issues, doesn't value the things you do for him, and may be a homophobe. Sure, I've assumed those things based on one side of a story summed up in two sentences, but I stand by it.
KICK HIM TO THE CURB, GURL. Or keep some breath mints by the bed. Either will work, really.